Hey Fritsl -
Can you try the following to see if it resolves the issues
Workaround
- Close the editor
- Go to ~/Library/Preferences/Unreal Engine/ProjectNameEditor/Mac/ and open SourceControlSettings.ini
- Set ExecutableLocation=/Users/Shared/UnrealEngine/4.12/Engine/Binaries/ThirdParty/svn/Mac/bin/svn
- Save the file
- Open ProjectName in UE4Editor