ACS azure for published application - azure

Question

Hy guys ,
I developed a WebForms application using VS 2012 . I've published it on Azure .
After that I integrated ACS ( i've set the URL to my allready published application)
I published the application again , but it doesn't work .
After I've registered myself (for ex using Yahoo or LiveID) I've got this error :
Server Error in '/' Application.
The data protection operation was unsuccessful. This may have been caused by not having the user profile loaded for the current thread's user context, which may be the case when the thread is impersonating.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Security.Cryptography.CryptographicException: The data protection operation was unsuccessful. This may have been caused by not having the user profile loaded for the current thread's user context, which may be the case when the thread is impersonating.
Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
Stack Trace:
[CryptographicException: The data protection operation was unsuccessful. This may have been caused by not having the user profile loaded for the current thread's user context, which may be the case when the thread is impersonating.]
System.Security.Cryptography.ProtectedData.Protect(Byte[] userData, Byte[] optionalEntropy, DataProtectionScope scope) +379
System.IdentityModel.ProtectedDataCookieTransform.Encode(Byte[] value) +52
[InvalidOperationException: ID1074: A CryptographicException occurred when attempting to encrypt the cookie using the ProtectedData API (see inner exception for details). If you are using IIS 7.5, this could be due to the loadUserProfile setting on the Application Pool being set to false. ]
System.IdentityModel.ProtectedDataCookieTransform.Encode(Byte[] value) +167
System.IdentityModel.Tokens.SessionSecurityTokenHandler.ApplyTransforms(Byte[] cookie, Boolean outbound) +57
System.IdentityModel.Tokens.SessionSecurityTokenHandler.WriteToken(XmlWriter writer, SecurityToken token) +658
System.IdentityModel.Tokens.SessionSecurityTokenHandler.WriteToken(SessionSecurityToken sessionToken) +86
System.IdentityModel.Services.SessionAuthenticationModule.WriteSessionTokenToCookie(SessionSecurityToken sessionToken) +144
System.IdentityModel.Services.SessionAuthenticationModule.AuthenticateSessionSecurityToken(SessionSecurityToken sessionToken, Boolean writeCookie) +82
System.IdentityModel.Services.WSFederationAuthenticationModule.SetPrincipalAndWriteSessionToken(SessionSecurityToken sessionToken, Boolean isSession) +216
System.IdentityModel.Services.WSFederationAuthenticationModule.SignInWithResponseMessage(HttpRequestBase request) +860
System.IdentityModel.Services.WSFederationAuthenticationModule.OnAuthenticateRequest(Object sender, EventArgs args) +369
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +136
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69
What should i do ?
I've set the URL's correctly. I don't have in web.config any reffernces of "localhost"..
I don't know what I must set additionly for this to work..

Answer 1

By default WIF uses DPAPI to encrypt cookies. Switch to cert based encryption. See this answer:
Is it possible to run WIF without LoadUserProfile = True

Answer 2

Vittorio Bertocci answers the question here
http://www.cloudidentity.com/blog/2013/01/28/running-wif-based-apps-in-windows-azure-web-sites-4/
DPAPI is not available in the cloud web apps and 4.5 has a simple solutions