An unhandled exception has occurred: Malformed URL in Release mode in .net core 2.0 app - release

Question

I have a .net core 2.0 app which uses IdentityServer 4. it works perfectly in development mode. then I published it for production mode and tested. when I click a (that action has a method to generated accesstoken) link I got an error like below,
An unhandled exception has occurred: Malformed URL
then error occurs here in production(Release) mode:
var disco = await IdentityModel.Client.DiscoveryClient.GetAsync(_configuration.GetSection("Settings").GetSection("DiscoveryClient").Value);
above DiscoveryClient is http not https
here is the full description of the error ..
Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[0]
An unhandled exception has occurred: Malformed URL
System.InvalidOperationException: Malformed URL
at IdentityModel.Client.DiscoveryClient.ParseUrl(String input)
at IdentityModel.Client.DiscoveryClient..ctor(String authority, HttpMessageHandler innerHandler)
at IdentityModel.Client.DiscoveryClient.<GetAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
is this because 'https'. I have no idea what is happening.hope your help with this.

Answer 1

This is a pretty old post, but it still might help someone. I had this exact same issue, only that the URL that I was passing in was perfectly fine. The problem on my side was that the IdentityServer Authority URL was misconfigured, causing it to throw the same exception.

Answer 2

Here is code snippet from DiscoveryClient's ParseUrl showing when it throws that exception:
public static DiscoveryEndpoint ParseUrl(string input)
{
var success = Uri.TryCreate(input, UriKind.Absolute, out var uri);
if (success == false)
{
throw new InvalidOperationException("Malformed URL");
}
if (!DiscoveryEndpoint.IsValidScheme(uri))
{
throw new InvalidOperationException("Malformed URL");
}
Here is the code for DiscoveryEndpoint's IsValidScheme method:
public static bool IsValidScheme(Uri url)
{
if (string.Equals(url.Scheme, "http", StringComparison.OrdinalIgnoreCase) ||
string.Equals(url.Scheme, "https", StringComparison.OrdinalIgnoreCase))
{
return true;
}
return false;
}
Based on this the exception is not thrown because the url is using http.
Try calling
new Uri(_configuration.GetSection("Settings").GetSection("DiscoveryClient").Value, UriKind.Absolute)
before your call to 'IdentityModel.Client.DiscoveryClient.GetAsync' so that you can see what exception is thrown by the Uri constructor.