Mixed mode assembly is built against version 'v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.

Question

An unhandled exception of type 'System.IO.FileNotFoundException' occurred in mscorlib.dll

Mixed mode assembly is built against version 'v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.

I tried the below solution:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0"/>
</startup>
</configuration>

It is working fine for Xp3 but not for windows 7. Any suggestions.

John Penn · Answer

Try specifying the full v4.0 version number in the supportedRuntime setting (for example version=v4.0.30319).

Sam Hobbs · Answer

My suggestion is to provide more information. Are you using DirectX? I am not as knowledgeable as others are on this subject but I can at least suggest what you should provide to assist others to assist you. The best solution is to determine what is using version 'v2.0.50727' of the runtime and either re-build it using version 4 or get a newer version of the software that uses version 4 of .Net. Do you at least know what it is that is using version 'v2.0.50727'? If not then perhaps someone can explain how to determine that.