Mixed mode assembly is built against version ‘v2.0.50727′ of the runtime

Question

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

Answer 1

Try to use this exact startup tag in your app.config under configuration node

<startup useLegacyV2RuntimeActivationPolicy="true">
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
    <requiredRuntime version="v4.0.20506" />
  </startup>