For those who come across a similar situation where Joplin is simply inaccessible (ie cannot access plugins, options, etc.), I listed in brief how I resolved it. Thanks to @personalizedrefriger for some direction on file locations and troubleshooting.

For reference I'm using Joplin Cloud so I can't speak to Dropbox etc. success/failure. I also uninstalled and reinstalled Joplin prior to these steps but I don't believe it's necessary.

  1. Navigate to C:\Users\YourUserName.config and copy the \joplin-desktop folder to a safe location as a precaution.
  2. Afterwards, delete that original \joplin-desktop folder.
  3. Open Joplin and sign in with your account info if using Joplin Cloud.
  4. In my case Joplin simply refused to sync so I restored a local backup. Restore took a long time because of the amount of data I have so expect a lengthy wait time if you have a large data footprint.
  5. Check your Synchronization & Encryption settings and re-enter as needed.
  6. I chose to wait on the sync to complete before using Joplin again. There were significant time delays and it took more than a week to sync everything. If you have the time and patience, then I recommend it. The sync results showed multiple errors on notes that previously didn't have issue so allowing Joplin Cloud to sort it out seemed like a smart move.

Eventually Joplin Cloud finished the sync but had a lot of difficulty resolving decryption errors. The app just continued to attempt decryption and fail. After a couple additional days it resolved itself to where a few notes were isolated as unable to decrypt and I simply deleted them (less than a dozen notes which were all old but previously had no issues).

I can't say for certain what occurred originally but the combination of errors, delays and decryption problems point to Joplin Cloud.

Tip: If you really get into a pinch you can create a new profile and restore your local backup offline to ensure it doesn't get locked in a sync error cycle and crash the program. This allows you to access the notes.

Notes:

  • I strongly recommend creating backups if you're not already doing so.
  • The backup options recommend a single .jex file to prevent the loss of folder structure and note links. This is important to me so I follow that directive. However, I'm going to look at singularly backing up folders that are of higher importance so that I can restore and access them quicker should something like this happen again. In my case it makes a lot of sense to pick specific data to restore in a crash type scenario when time is an issue.

Hope this helps.