[.net] Mixed mode assembly is built against version ‘v2.0.50727′ of the runtime
The exception clearly identifies some .NET 2.0.50727 component was included in .NET 4.0. In App.config file use this:
<startup useLegacyV2RuntimeActivationPolicy="true" />
It solved my problem
I'm getting the following exception:
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.
as I was trying to export crystal report from my WPF program...
I have added the following in the app.config already...
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
</startup>
<runtime>
<NetFx40_LegacySecurityPolicy enabled="true"/>
</runtime>
Any experts can help????
Reference I found: http://www.davidmoore.info/2010/12/17/running-net-2-runtime-applications-under-the-net-4-runtime
Please add attribute useLegacyV2RuntimeActivationPolicy="true" in your applications app.config file.
Old Value
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
</startup>
New Value
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.1"/>
</startup>
It will solve your problem.
For me this was thrown when running unit tests under MSTest (VS2015). Had to add
<startup useLegacyV2RuntimeActivationPolicy="true">
</startup>
in
C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\CommonExtensions\Microsoft\TestWindow\TE.ProcessHost.Managed.exe.config
.net