I've managed to get workbench to boot again by unmounting my P:/ drive. Looks like for whatever reason, if the file path in the "Source Data Directory" field is actually valid, workbench won't boot (at least for me). I was able to recreate this issue by setting the filepath to an arbitrary directory, then rebooting, which crashed workbench. Renaming that directory then allowed workbench to boot. If anyone knows what might be the issue here, please let me know.