What is the difference between the three following scenarios (in an app.config files of an exe)?
<startup>
<supportedRuntime version="v4.0" />
<supportedRuntime version="v2.0" />
</startup>
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" />
<supportedRuntime version="v2.0" />
</startup>
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0" />
</startup>
I've read the MS documentation on it and some blogs but it still isn't very clear to me exactly what happens and when to use which.
EDIT
I have a situation where a third party application was compiled with CLR 2 (and also uses legacy COM) and the allowed extensions that I've made for the application are compiled with CLR 4. So, recompiling the application is not an option for me. I just need to know the impact of the three scenarios.