If you can't launch at all because of some bad plugins...
You can move your plugins to a temp desktop folder so that Studio One doesn't scan any, to launch to be able to get into the Preferences > Advanced > Services settings to then maybe disable entire specific single plugin formats to troubleshoot as you go about putting some of them back to try to find the offending plugin.
The following folders are the default installation folders for plug-ins on Mac:
Macintosh HD:/Library/Audio/Plug-Ins/Components/ (AU)
Macintosh HD:/Library/Audio/Plug-Ins/VST/ (VST)
Certain plug-ins may install themselves to the <user> folder. This folder is hidden by default, here's how to access hidden folders.
Macintosh HD:/Users/[Your Username]/Library/Audio/Plug-Ins/Components/ (AU)
Macintosh HD:/Users/[Your Username]/Library/Audio/Plug-Ins/VST/ (VST)
Note: It's a little easier on Windows where you can just temp rename your plugin folders. Doing that on OSX is not recommended.