WCF Server Application Unavailable - how to run application written in .NET4.0 (IIS6+)

Question

Hello, I am trying to run simple application (e.g. generated from template by VS.NET 2010) on IIS6.

I changed it to run with .NET 4.0 (its application pool) and checked with regiis (this pool has 4.0). I also changed all possible httpHandlers (svc etc), to run with NET4.0. All possible rights are checked (i think so).

Almost every request results in "Server Application Unavailable" (sometimes it is empty page with -2146232576 (0x80131700) value) and "...Please review this log entry to discover what caused this error to occur." but EventViewer and IIS Log are empty.

Any ideas? Where to find error details?

Answer 1

Do you run any 2.0 apps on the same server? If yes it could be the issue in case they bot use the same application pool. The application tool itself doesn't have any .NET version setting, it's per virtual directory (application). But you can't use the same application pool to run applications with different versions of .NET Framework apps.

Answer 2

Create two seperate app pools one for your CLR 2.0 and CLR 4.0, the older clr can not host both CLRs, there was a similar issue with 1.1 and 2.0.

cheers