[.Net]More than one exclusive group is not allowed

I have a ASP.Net web application deploy on 2 load balaced web servers with its source code stored on shared folder of file server.

I keep getting [more than one exclusive group is not allowed] while trying to browse my web site.

After digging into event log, I also found Event ID:1310 with Event Code:3008 were logged on Event log

This exception is thrown due to mCAS (code access security) exclusive policy were set again SAME code group twice, so that .Net could not decide which policy should be applied.

We can fix that in a simple way:

run

[%WINDOWS%\Microsoft.Net\Framework\v2.0.50727\caspol - rg [%group_name_or_lable%]

to remove duplicated policy.