Unknown block type. Stream might be corrupted.

I got this error after from Visual Studio 2010 saving Layout.css. When I refreshed my page in a browser, the error occurred. The site is in IIS 7.5 using SQL Express on my Windows 7 dev machine. I had made css changes, saved and refreshed many times earlier in the day.

Server Error in '/' Application.Unknown block type. Stream might be corrupted. 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.IO.InvalidDataException: Unknown block type. Stream might be corrupted.

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:

[InvalidDataException: Unknown block type. Stream might be corrupted.]
System.IO.Compression.Inflater.Decode() +8805807
System.IO.Compression.Inflater.Inflate(Byte[] bytes, Int32 offset, Int32 length) +118
System.IO.Compression.DeflateStream.Read(Byte[] array, Int32 offset, Int32 count) +85
Microsoft.IdentityModel.Web.DeflateCookieTransform.Decode(Byte[] encoded) +214
Microsoft.IdentityModel.Tokens.SessionSecurityTokenHandler.ApplyTransforms(Byte[] cookie, Boolean outbound) +189
Microsoft.IdentityModel.Tokens.SessionSecurityTokenHandler.ReadToken(XmlReader reader, SecurityTokenResolver tokenResolver) +877
Microsoft.IdentityModel.Tokens.SessionSecurityTokenHandler.ReadToken(Byte[] token, SecurityTokenResolver tokenResolver) +109
Telerik.Sitefinity.Security.Claims.SitefinitySessionAuthenticationModule.ReadToken(Byte[] sessionCookie) +299
Telerik.Sitefinity.Security.Claims.SitefinitySessionAuthenticationModule.OnAuthenticateRequest(Object sender, EventArgs eventArgs) +95
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +80
System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +165

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.18034

I was using fluent API to create pages and suddenly I got this above mentioned error. Is 5.4  a unstable version?

Was your trace the same as Michael's?

I have actually received this error on 2 other occasions. It seems to happen when doing save operations, either file based or using the GUI and saving a Page. In all circumstances, I have removed the site and the app pool from IIS, made new ones pointing to the same set of files and the site worked fine then. So it would appear the corruption occurs in IIS and since it has happened when simply saving a file, I do not think Sitefinity is to blame, at least not until I can get a guaranteed repro process.

Michael,

Do you have .net 4.5 installed? System.IO.Compression got some improvements in that version and might help out. :)

yes, I am working in VS2012 on Win 7 using IIS. I just moved the code to TFS and the DB to a test db so other developers can share. In doing so I am now using IIS Express 8 to minimize the setup time for a new developer on the project. If I receive the issue again with IIS Express 8 I will take the time and try to repro the situation.

Hi,

 We have not encountered this error before. If you reproduce it again, would it be possible to submit a support ticket, so that we can investigate it and after that share the results in this thread.