Thanks!
Can you try the following?
- Quit Local if it’s running
- Update VirtualBox. Here’s the latest download link: http://download.virtualbox.org/virtualbox/5.2.6/VirtualBox-5.2.6-120293-OSX.dmg
- Re-open Local
- Go to Preferences » Add-ons and disable Faster Docker Volumes
- Try updating a theme/plugin
If that fixes the issue, try upgrading to Local 2.2.1 (pre-release) and then re-enable Faster Docker Volumes.