Currently the solution is managed by SVN and I want to switch to git. When I do Tools->Options->Source Control->Plug-in Selection and change plug-in I get this dialog:
I never get past that, when I open the .sln again it is still SVN.
I have a feeling I have done this many times in the past.
Additional info: The files are already managed by git, I just cloned it using git extensions and it was np. The issue is in VS.
Suggestion: Don't bother with switching. Remove it from source control (SVN) and check it in anew (git). Or, if removing it by Visual Studio tools doesn't work, here's how you do it manually:
Edit: Manually removing this from the .sln file did the trick:
GlobalSection(SubversionScc) = preSolution Svn-Managed = True Manager = AnkhSVN - Subversion Support for Visual Studio EndGlobalSection