Replying to Jeichberger, I don't know if the below will help. I had issues with the RegSvr32 error (I have a windows 7 x64 machine).
After updating and restarting, re-run the update check (you may need to check multiple times depending how far behind you are).
Then reinstall or repair the 4 Visual C++ redistributables. x86 and x64 for 2017 and x86 and x64 for 2013. One pair is specified for the OBS install and one pair is for the plugin. (I don't know if running as admin makes any difference for the redistributables, I would assume not)
Then try the OBS camera install again (try both methods if one doesn't work).
If the x64 version plugin works but the x86 plugin version does not work, then you will probably still see the OBS camera in the OBS program, but other programs (ie Skype) might not see the OBS camera.