I'm running macOS Catalina (10.15.7). I had OBS working fine with the newish built-in virtual cam feature. Then I did the automatic upgrade to OBS 26.1.2, and after that OBS would crash on startup every time with a code signature error. I looked through it and realized it was specifically crashing on the obs-mac-virtualcam plugin.
Manually removing the plugin like this allowed OBS to run again:
sudo rm -rf /Library/CoreMediaIO/Plug-Ins/DAL/obs-mac-virtualcam.plugin/
Once OBS is running again, clicking the "Start Virtual Camera" button causes OBS to prompt you for permission to modify the system. If you grant it with your password, OBS will recreate the plugin directory listed above with its latest version, getting everything back to normal.
I thought I would share this in case anyone else was running into the same problem. I saw some nondescript threads here asking for help with crashes.
Manually removing the plugin like this allowed OBS to run again:
sudo rm -rf /Library/CoreMediaIO/Plug-Ins/DAL/obs-mac-virtualcam.plugin/
Once OBS is running again, clicking the "Start Virtual Camera" button causes OBS to prompt you for permission to modify the system. If you grant it with your password, OBS will recreate the plugin directory listed above with its latest version, getting everything back to normal.
I thought I would share this in case anyone else was running into the same problem. I saw some nondescript threads here asking for help with crashes.