>>Sounds like a hi-tech version of dll hell :).
>
>Actually it's not as long as you have a reasonably recent version of .NET installed. .NET 4.0 was a nightmare because they had 2 different versions that you couldn't easily tell apart.
>
>Sorted with .NET 4.5 and later which is forwards and backwards compatible.
>
>+++ Rick ---

In the end I found the error: There was another process that loaded another .NET dll (through NET Extender), which was compiled in .NET 2.0. Apparently this process initialized the clr for that .NET Version, and when I subsequently tried to load wwDotNetBridge, it was still stuck in Version 2.0.

What I did was to load the wwDotNetBridge once before anything else (only the loading process without doing anything else with it), and because of that it seems to remember the newer clr Version. So when I then load again wwDotNetBridge at a later point it succeeds.