Our company is developing our new applications using Service Fabric.
A common problem we have, multiple developers use queues, databases, storages that are on remote servers, and each one has different configuration for this, all the settings are stored on ApplicationParameters file per environment, for Local development there is a single Local.5Node.xml. It is very common developers checkin their credentials and overwrite others when we get latest version of these files.
I'm trying to customize the ServiceFabric deployment script 'Deploy-FabricApplication.ps1' to use a custom PublishProfile depending on windows credentials of logged user. I can achieve that updating the deployment file, it works well when we deploy using the publish, but it seems that the default behavior of ServiceFabric when we hit F5(debug) is overwrite the parameters with a specific Local.5Node.xml application parameters.
I explored all service fabric .ps1 files and couldn't find where this is defined. I guess this is defined on .targets file, so I don't know how can I avoid this default behaviour.
Is there any other approach to use custom PublishProfiles on local development machines other than Local.5Node.xml?
I actually just ran into this with setting up some team specific environments. I borrowed information from the following sources:
Web Config Transformation
Replace String In File With MSBUILD
I added multiple parameters files based on what was needed for the different teams. Each one containing their specific resource settings.
I also added a Local.1Node.Template.xml and Local.5Node.Template.xml. I even removed the Local.1Node.xml and Local.5Node.xml from source control and set them up to be ignored while leaving them in the projects so that Visual Studio doesn't think they are truly missing. The contents of the 1Node (5Node is the same except for replacing 1Node with 5Node) are as follows:
<?xml version="1.0" encoding="utf-8"?>
<PublishProfile xmlns="http://schemas.microsoft.com/2015/05/fabrictools">
<ClusterConnectionParameters />
<ApplicationParameterFile Path="..\ApplicationParameters\Local.1Node.$(Configuration).xml" />
</PublishProfile>
I then edited the sfproj file for the Service Fabric project to contain the following MSBuild Task and Target:
<UsingTask TaskName="ReplaceFileText" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
<ParameterGroup>
<InputFilename ParameterType="System.String" Required="true" />
<OutputFilename ParameterType="System.String" Required="true" />
<MatchExpression ParameterType="System.String" Required="true" />
<ReplacementText ParameterType="System.String" Required="true" />
</ParameterGroup>
<Task>
<Reference Include="System.Core" />
<Using Namespace="System" />
<Using Namespace="System.IO" />
<Using Namespace="System.Text.RegularExpressions" />
<Code Type="Fragment" Language="cs">
<![CDATA[
File.WriteAllText(
OutputFilename,
Regex.Replace(File.ReadAllText(InputFilename), MatchExpression, ReplacementText)
);
]]>
</Code>
</Task>
</UsingTask>
<Target Name="UpdateProfile" BeforeTargets="UpdateServiceFabricApplicationManifest">
<ReplaceFileText InputFilename="PublishProfiles\Local.1Node.Template.xml" OutputFilename="PublishProfiles\Local.1Node.xml" MatchExpression="\$\(Configuration\)" ReplacementText="$(Configuration)" />
<ReplaceFileText InputFilename="PublishProfiles\Local.5Node.Template.xml" OutputFilename="PublishProfiles\Local.5Node.xml" MatchExpression="\$\(Configuration\)" ReplacementText="$(Configuration)" />
</Target>
The final step was to setup the different Build Configurations for the teams. I created a FT1-Debug through FT6-Debug based on the Debug configuration in the Service Fabric Service project and the Service Fabric Host project. I left all of my other projects alone.
At this point everyone on the different teams can debug locally with the correct configuration for the cluster they are doing work in just by changing the Build Configuration and pressing F5 to debug.
The VS extension for Service Fabric define a hard coded publish profile when we debug the solution using Visual Studio, it check how many nodes my cluster has and create a link to Local.5Node.xml and Local.1Node.xml depending how many nodes my cluster have.
To accomplish the same results, we end up using custom Application Parameters per developer and each developer update the Publish Profile (Local.5node.xml) to point to their respective Application parameter files.
It is not automated as the required feature, but can solve the main problem.
It is possible in Azure Web App to override web.config AppSettings section easily. E.g. if I have the following web.config:
<appSettings>
<add key="AllowedCORSOrigin" value="http://localhost:26674"/>
</appSettings>
I can override it in the app settings UI in the portal like that:
I have also a custom section in the web.config:
<AdWordsApi>
<add key="OAuth2RefreshToken" value="TOKEN" />
</AdWordsApi>
Is it possible to override it somehow as well? I have tried AdWordsApi.OAuth2RefreshToken and AdWordsApi:OAuth2RefreshToken, but that does not work that easily.
P.S. It's interesting to know if it's possible with other custom sections like e.g if I want another authentication mode on the server.
<system.web>
<authentication mode="None" />
</system.web>
Short answer is that it is not possible.
The mechanism you describes only works with App Settings and Connection Strings. High level, the way it works is:
Your Azure App Settings become environment variables
At runtime, a special module sets those dynamically in the .NET config system. Note that the physical web.config is never modified.
But it would be hard to make such mechanism work on arbitrary config sections, as those could not be dynamically affected without modifying the physical file.
If you are using Visual Studio use web.config transformations to change configuration settings depending on whether you are running locally or deploying to Azure:
How to Transform Web.config
In simple terms you create one more more build configurations (typically Debug & Release). In your Visual Studio solution right-click on your existing web.config file and click "Add Config Transform", this will create a Web.Debug.Config and Web.Release.Config file which you can then customise with specific settings depending on the environment. Link this with your Azure build configuration and you can then have any combination of settings for local and remote deployment.
This is old but leaving this reference to how to use Azure Resource Manager to potentially solve this.
You can transform the values by the listed in VSTS by doing the following steps in App.Release.config:-
Add xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform" in configuration section
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
</configuration>
Add xdt:Transform="Replace" in custom section like below
<AdWordsApi xdt:Transform="Replace">
<add key="OAuth2RefreshToken" value="TOKEN" />
</AdWordsApi>
Create variable token in the release pipeline e.g OAuth2RefreshToken
Then in file config use it as following
<AdWordsApi xdt:Transform="Replace">
<add key="OAuth2RefreshToken" value="#{OAuth2RefreshToken}#" />
</AdWordsApi>
If you are adding any in web.config --> Appsetting, you can overirde it in Azure App Service using variable prefix
Key Name: APPSETTING_AllowedCORSOrigin
Value: http://localhost:26674
https://learn.microsoft.com/en-us/azure/app-service/reference-app-settings?tabs=kudu%2Cdotnet#variable-prefixes
I have searched through dozens of posts (most of them are a few years old). I would like to speed up the first load of our app and have not found the correct configuration combination to do so on Server 2008 R2. I have it working well on Server 2012 R2 - IIS 8.5. But we still have some sites on Server 2008 R2. What I have done for Server 2008 R2 is:
Installed 'Application Initialization 1.0 for IIS 7.5' and rebooted
Edited applicationHost.config under applicationPools to add:
'startMode="AlwaysRunning"'
Edited applicationHost.config under sites to add 'preloadEnabled="true"' to application path
Edited my application's web.config file to add 'applicationInitialization doAppInitAfterRestart="true"' under system.WebServer
This seemingly has no effect. What am I missing? FWIW, I am using ApplicationPoolIdentity and have Anonymous & Forms Authentication Enabled and ASP.NET Impersonation, Basic, & Windows Authentication Disabled. Any hints are greatly appreciated. Thanks.
After point 2 I would do the following:
Go to your Server in IIS, then double-click on ConfigurationEditor, then Choose:
1-system.applicationHost/applicationPools->Click on (Collection)-> Choose your Pool->Check if "autoStart" is "true" and validate that startMode is "AlwaysRunning"(already done on your point 2)->Then Close the window->Click on apply
2-system.applicationHost/sites->Click on (Collection)->Now Click on the site you want and turn serviceAutoStart to "true",if your site is inside "Default Web Site" press (Collection) below->Now choose your site->Turn preloadEnabled to "true" and serviceAutoStartEnabled to "true" as well.-> close all and apply.
To test go to your pool restarted it in IIS and check in your task manager that w3wp.exe is using your CPU.After some seconds w3wp.exe will stop using your CPU.
For those like me looking for an answer years after all documentation seems to have been wiped from the internet, this worked for me.
Download and install Application Initialization Module for IIS 7.5 from one of the following links (requires reboot): Link 1 Link 2 Link 3
Edit C:\Windows\System32\inetsrv\config\applicationHost.config
Find the configuration\system.applicationHost\applicationPools configuration section
Add autoStart="true" to the application pool used by your web app, so this
<add name="MyCoolAppPool" startMode="AlwaysRunning" enable32BitAppOnWin64="true" managedRuntimeVersion="v4.0" />
becomes this:
<add name="MyCoolAppPool" autoStart="true" startMode="AlwaysRunning" enable32BitAppOnWin64="true" managedRuntimeVersion="v4.0" />
Find the configuration\system.applicationHost\sites\site configuration section
Find the application node for your web app
Add preloadEnabled="true" so the node changes from this
<application path="/UrlPathToMyApp" applicationPool="MyCoolAppPool">
<virtualDirectory path="/" physicalPath="C:\Virtual Directories\MyCoolApp" />
</application>
to this
<application path="/UrlPathToMyApp" preloadEnabled="true" applicationPool="MyCoolAppPool">
<virtualDirectory path="/" physicalPath="C:\Virtual Directories\MyCoolApp" />
</application>
Finally, restart IIS.
Rick Strahl explained a hiccup he had to deal with when installing/configuring it: Add AppWarmupModule to <globalModules> like this:
<globalModules>
<add name="AppWarmupModule" image="%SystemRoot%\system32\inetsrv\warmup.dll" />
</globalModules>
I need to keep several versions of a application running at the same time on Service Fabric.
1.0
1.1
....
Instead of updating and replacing versions, I need to keep them online together.
Is it possible?
Thanks!
As Matt Thalman said, is possible to have different versions of same app running in the Service Fabric cluster.
I've tested with the sample app WordCount(http://aka.ms/servicefabric-wordcountapp). To see more details how download the app and deploy it, see https://azure.microsoft.com/en-us/documentation/articles/service-fabric-get-started-with-a-local-cluster/
I've duplicated the WordCount as WordCountV1 and WordCountV2.
Then I've changed the /ApplicationManifest.xml to have different ApplicationTypeVersion on each package. It's necessary for displaying the current version of the App in the Cluster Manager because both apps are shown grouped by the ApplicationTypeName.
V1
<ApplicationManifest xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ApplicationTypeName="WordCount" ApplicationTypeVersion="1.0.0" xmlns="http://schemas.microsoft.com/2011/01/fabric">
V2
<ApplicationManifest xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ApplicationTypeName="WordCount" ApplicationTypeVersion="2.0.0" xmlns="http://schemas.microsoft.com/2011/01/fabric">
Yet I've changed the /WordCountWebServicePkg/Code/wwwroot/index.html file to have different content on both packages.
Is necessary to specify different Endpoints, so I've changed the file /WordCountWebServicePkg/ServiceManifest.xml in both packages to respond on different Ports
V1
<Endpoint Name="ServiceEndpoint" Type="Input" Protocol="http" Port="8081" />
V2
<Endpoint Name="ServiceEndpoint" Type="Input" Protocol="http" Port="8082" />
The last step is to use different a ApplicationName to publish packages:
V1
Publish-NewServiceFabricApplication -ApplicationPackagePath c:\ServiceFabric\WordCountV1.sfpkg -App
licationName "fabric:/WordCountV1"
V2
Publish-NewServiceFabricApplication -ApplicationPackagePath c:\ServiceFabric\WordCountV2.sfpkg -App
licationName "fabric:/WordCountV2"
Both apps are published side-by-side and we can have more control on version update with that.
V1
http://localhost:8081/
V2
http://localhost:8082/
Hope it helps!
PS: Azure Service Fabric documentation team, this subject can be good to be in public docs
Yes, you can do this as long as you have different application names. The application name is specified in the application parameters file in your Service Fabric Application (.sfproj) project. That application name value is used when Visual Studio invokes Service Fabric's New-ServiceFabricApplication PowerShell cmdlet. This means you can have two apps running in a cluster with the same application type and version as long as they have different application names. Or you could have different versions of the application type if you wish. As long as they have different application names, it doesn't matter; they're treated as unique applications.
I've encountered an error deploying a site to a server. When trying to load the home page, or access authentication on the new site in IIS, I get the error:
Config Error: This configuration section cannot be used at this path.
This happens when the section is locked at a parent level. Locking is
either by default (overrideModeDefault="Deny"), or set explicitly by a
location tag with overrideMode="Deny" or the legacy
allowOverride="false".
More detail can be found here, in Scenario 7 matches my hex error code.
The solution given on the linked site above is to set Allow for overrideModeDefault in the section mentioned in my error, in the applicationHost.config file. In my case, under Security in system.webServer. But if I look at the applicationHost.config on my local computer, where the site is properly deployed already, that section is set to Deny.
If this solution is correct, how is my local instance running just fine with the same web.config? According to my applicationHost.config, that section should be locked, but it's not. I'd prefer to not change the applicationHost.config file, because there are many other sites running on that server. Is there another solution?
I had the same problem. Don't remember where I found it on the web, but here is what I did:
Click "Start button"
in the search box, enter "Turn windows features on or off"
in the features window, Click: "Internet Information Services"
Click: "World Wide Web Services"
Click: "Application Development Features"
Check (enable) the features. I checked all but CGI.
btw, I'm using Windows 7. Many comments over the years have certified this works all the way up to Windows 10 and Server 2019, as well.
You could also use the IIS Manager to edit those settings.
Care of this Learn IIS article:
Using the Feature Delegation from the root of IIS:
You can then control each of machine-level read/write permissions, which will otherwise give you the overrideMode="Deny" errors.
For Windows Server 2012 and IIS 8, the procedure is similar.
The Web Server (IIS) and Application Server should be installed, and you should also have the optional Web Server (IIS) Support under Application Server.
Browse to “C:\Windows\System32\inetsrv\config” (you will need administrator rights here)
Open applicationHost.config
Note: In IISExpress and Visual Studio 2015 the applicationHost.config is stored in $(solutionDir).vs\config\applicationhost.config
Find the section that showed up in the “config source” part of the error message page. For me this has typically been “modules” or “handlers”
Change the overrideModeDefault attribute to be Allow
So the whole line now looks like:
<section name="modules" allowDefinition="MachineToApplication" overrideModeDefault="Allow" />
After saving the file, the page loaded up fine in my browser.
Warning:
Editing applicationHost.config on 64-bit Windows
You need to unlock handlers. This can be done using following cmd command:
%windir%\system32\inetsrv\appcmd.exe unlock config -section:system.webServer/handlers
Maybe another info for people that are getting this error on IIS 8, in my case was on Microsoft Server 2012 platform. I had spend couple of hours battling with other errors that bubbled up after executing appcmd. In the end I was able to fix it by removing Web Server Role and installing it again.
1. Open "Turn windows features on or off" by: WinKey+ R => "optionalfeatures" => OK
Enable those features under "Application Development Features"
Tested on Win 10 - But probably will work on other windows versions as well.
I ran these two commands from an elevated command prompt:
%windir%/system32/inetsrv/appcmd unlock config /section:anonymousAuthentication
%windir%/system32/inetsrv/appcmd unlock config /section:windowsAuthentication
As per my answer to this similar issue;
Try unlocking the relevant IIS configuration settings at server level, as follows:
Open IIS Manager
Select the server in the Connections pane
Open Configuration Editor in the main pane
In the Sections drop down, select the section to unlock, e.g. system.webServer > defaultPath
Click Unlock Attribute in the right pane
Repeat for any other settings which you need to unlock
Restart IIS (optional) - Select the server in the Conncetions pane, click Restart in the Actions pane
This Did the trick for me, for IIS 8 Windows server 2012 R2
Go to "Turn on Features"
Then go to all default setting , Next, Next, Next etc..
Then, select as shown below,
Then reset IIS (optional) but do it safer side.
This is an additional solution as its a generic problem everyone have different of problem and thus different solution. Cheers!
The best option is to Change Application Settings from the Custom Site Delegation
Open IIS and from the root select Feature Delegation and then select Application Settings and from the right sidebar select Read/Write
On Windows Server 2012 with IIS 8 I have solved this by enabling ASP.NET 4.5 feature:
and then following ken's answer.
To fix this open up the IIS Express applicationhost.config. This file is stored at C:\Users[your user name]\Documents\IISExpress\config\applicationhost.config
Update for VS2015+: config file location is $(solutionDir).vs\config\applicationhost.config
Look for the following lines
<section name="windowsAuthentication" overrideModeDefault="Deny" />
<section name="anonymousAuthentication" overrideModeDefault="Deny" />
<add name="WindowsAuthenticationModule" lockItem="true" />
<add name="AnonymousAuthenticationModule" lockItem="true" />
Change those lines to
<section name="windowsAuthentication" overrideModeDefault="Allow" />
<section name="anonymousAuthentication" overrideModeDefault="Allow" />
<add name="WindowsAuthenticationModule" lockItem="false" />
<add name="AnonymousAuthenticationModule" lockItem="false" />
Save it and refresh Asp.net Page.
In our case on IIS 8 we found the error was produced when attempting to view Authentication" for a site, when:
The server Feature Delegation marked as "Authentication - Windows" = "Read Only"
The site had a web.config that explicitly referenced windows authentication; e.g.,
Marking the site Feature Delegation "Authentication - Windows" = "Read/Write", the error went away. It appears that, with the feature marked "Read Only", the web.config is not allowed to reference it at all even to disable it, as this apparently constitutes a write.
Seems that with IIS Express and VS 2015, there's a copy of the applicationHost.config file at $(solutionDir).vs\config\applicationhost.config so you'll need to make changes there. See this link: http://digitaldrummerj.me/iis-express-windows-authentication/
Make sure these lines are changed per below:
<section name="windowsAuthentication" overrideModeDefault="Allow" />
<section name="anonymousAuthentication" overrideModeDefault="Allow" />
<add name="WindowsAuthenticationModule" lockItem="false" />
<add name="AnonymousAuthenticationModule" lockItem="false" />
In my case it was that on server was not enabled "HTTP Activation" under .NET Framework Features. So for Windows Server 2012 the solution which worked for me was:
Server Manager -> Add roles and features -> Features -> make sure that under .NET Framework of version you want to use is checked "HTTP Activation"
The Powershell way of enabling the features (Windows Server 2012 +) - trim as needed:
Install-WindowsFeature NET-Framework-Core
Install-WindowsFeature Web-Server -IncludeAllSubFeature
Install-WindowsFeature NET-Framework-Features -IncludeAllSubFeature
Install-WindowsFeature NET-Framework-45-ASPNET -IncludeAllSubFeature
Install-WindowsFeature Application-Server -IncludeAllSubFeature
Install-WindowsFeature MSMQ -IncludeAllSubFeature
Install-WindowsFeature WAS -IncludeAllSubFeature
The error says that the configuration section is locked at the parent level.
So it will not be directly 1 config file which will resolve the issue,
we need to go through the hierarchy of the config files to see the inheritance
Check the below link to go through the File hierarchy and inheritance in IIS
https://msdn.microsoft.com/en-us/library/ms178685.aspx
So you need to check for the app config settings in the below order
ApplicationHost.config in C:windows\system32\inetsrv\config. Change the overrideModeDefault attribute to be Allow.
ApplicationName.config or web.config in the applications directory
Web.config in the root directory.
Web.config in the specific website (My issue was found at this place).
Web.config of the root web (server's configuration)
machine.config of the machine (Root's web.config and machine.config can be found at - systemroot\MicrosoftNET\Framework\versionNumber\CONFIG\Machine.config)
Go carefully through all these configs in the order of 1 to 6 and you should find it.
I noticed one answer that was similar, but in my case I used the IIS Configured Editor to find the section I wanted to "unlock".
Then I copied the path and used it in my automation to unlock it prior to changing the sections I wanted to edit.
. "$($env:windir)\system32\inetsrv\appcmd" unlock config -section:system.webServer/security/authentication/windowsAuthentication
. "$($env:windir)\system32\inetsrv\appcmd" unlock config -section:system.webServer/security/authentication/anonymousAuthentication
I needed to change the SSL settings on a subfolder when i got this nice message. In my case following action helped me out.
Opened C:\Windows\System32\inetsrv\config\applicationHost.config
And changed the value from overrideModeDefault="Deny" to "Allow"
<sectionGroup name="system.webServer">
...
<sectionGroup name="security">
<section name="access" overrideModeDefault="Allow" />
</sectionGroup>
In my case, I got this error because I was operating on the wrong configuration file.
I was doing this:
Configuration config = serverManager.GetWebConfiguration(websiteName);
ConfigurationSection serverRuntimeSection = config.GetSection("system.webServer/serverRuntime");
serverRuntimeSection["alternateHostName"] = hostname;
instead of the correct code:
Configuration config = serverManager.GetApplicationHostConfiguration();
ConfigurationSection serverRuntimeSection = configApp.GetSection("system.webServer/serverRuntime", websiteName);
serverRuntimeSection["alternateHostName"] = hostname;
in other words, I was trying to operate on the website's web.config instead of the global file C:\Windows\System32\inetsrv\config\applicationHost.config, which has a section (or can have a section) for the website. The setting I was trying to change exists only in the applicationHost.config file.
In my case, it was something else.
When I loaded the solution in a new version of Visual Studio, VS apparently created a new project-specific applicationhost.config file:
MySolutionDir\.vs\config\applicationhost.config
It started using the settings from the new config, instead of my already customized global IIS Express settings.
(\Users\%USER%\Documents\IISExpress\config\applicationhost.config)
In my case this was the setting that needed to be set. Of course it could be something else for you:
<section name="ipSecurity" overrideModeDefault="Allow" />
Received this same issue after installing IIS 7 on Vista Home Premium. To correct error I changed the following values located in the applicationHost.config file located in Windows\system32\inetsrv.
Change all of the following values located in section -->
<div mce_keep="true"><section name="handlers" overrideModeDefault="Deny" /> change this value from "Deny" to "Allow"</div>
<div mce_keep="true"><section name="modules" allowDefinition="MachineToApplication" overrideModeDefault="Deny" /> change this value from "Deny" to "Allow"</div>
Can You try this:
Go to application path where you're getting deny error, right click
Properties->Security tab
In that, change the permissions and check the checkbox read and write. Then it will work without any error hopefully.
For Windows Server 2008 and IIS 7, the procedure is similar.
please refer to this:
http://msdn.microsoft.com/en-us/library/vstudio/bb763178(v=vs.100).aspx
in add role service, u will see "Application Development Features"
Check (enable) the features. I checked all.
In my case I was getting this error when attempting to update the authentication settings in IIS also in addition to browsing. I was able to remove this error by removing the authentication setting from the web.config itself. Removing a problematic configuration section may be less invasive and preferable in some cases than changing the server roles and features too much:
Section Removed:
<security>
<authentication>
<windowsAuthentication enabled="true" />
</authentication>
</security>
I had the similar issue, but I used the following powershell script which helped me to achieve above steps in on button click.
#Install IIS
Import-Module ServerManager
Add-WindowsFeature Web-Server, Web-Asp-Net45, Web-Mgmt-Console, Web-Scripting-Tools, NET-WCF-HTTP-Activation45, Web-Windows-Auth
the list of features can be added or removed based on the requirement.
I had an issue where I was putting in the override = "Allow" values (mentioned here already)......but on a x64 bit system.......my 32 notepad++ was phantom saving them. Switching to Notepad (which is a 64bit application on a x64 bit O/S) allowed me to save the settings.
See :
http://dpotter.net/technical/2009/11/editing-applicationhostconfig-on-64-bit-windows/
The relevant text:
One of the problems I’m running down required that I view and possibly edit applicationHost.config. This file is located at %SystemRoot%\System32\inetsrv\config. Seems simple enough. I was able to find it from the command line easily, but when I went to load it in my favorite editor (Notepad++) I got a file not found error. Turns out that the System32 folder is redirected for 32-bit applications to SysWOW64. There appears to be no way to view the System32 folder using a 32-bit app. Go figure.
Fortunately, 64-bit versions of Windows ship with a 64-bit version of Notepad. As much as I dislike it, at least it works.
I had the same issue.
Resolved it by enabling Application Server feature. Restarted iis
after that.
This worked for me
Also in IIS 8 you can solve this problem by changing the server to IIS Express. Goto debug->Properties
In the Web select the server as IIS Express from the dropdown and then rebuild the solution
To make a change at Application Level (Web.Config):
Please remove the Trust Level from the web.config:
Actually I was getting this error when I was trying to host my Website on the Hosting Server where I don't have control on their Server. Removing the above line from my Application web.config solved my issue.