We haven't tried this plugin on our end yet, but one possible thing you could try would be to:
- Open Finder,
- From the Go menu choose Go To Folder
- Paste this into the box: ~/Library/Preferences/ and press Enter
- Inside the folder, locate and delete the .crashed_plugins file (it's a hidden file so if you don't see it you might have to press Cmd+Shift+. to toggle hidden files visibility on)
- Open ALK2 and see if it starts rescanning the plugin
The problem might be that the plugin crashed on a certain scan and got saved into the crashed_plugins list which then stops rescanning it (to make sure it does not crash the app). If that doesn't help, let us know (the best way is to send an email to firstname.lastname@example.org) and we'll try to recreate the issue on our machines.