I have a Visual Studio solution with mixed mode. Some projects are .Net Framework 4.0 while others are .Net Framework 2. This was solved by adding an app.config with:
<?xml version="1.0"?>
<configuration>
<startup useLegacyV2RuntimeActivationPolicy="true">
<supportedRuntime version="v4.0"sku=".NETFramework,Version=v4.0,Profile=Client"/></startup>
</configuration>
However, when I deploy this into an installation, it doesn't work. It gives out the message: 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 have tried to add the app.config to the installation ( so the file ends up in Program Files/..., and also renamed it app.exe.config. (I thought an app.exe.config would be created in the build, but it wasn't). The installation also contains a file "myApp".exe.config which contains the same as the app.config. This doesn't help either.