"UI Failed to load."

I’m getting this notice on the UI whenever I open it and a little red X on my Avast tray icon. Restart Service brings up an admin prompt but doesn’t do anything. What should I do?

Tried repair and reboot ? https://support.avast.com/en-us/article/Repair-Antivirus

If Repair doesn’t solve the problem, follow this: Clean Install of Avast:
https://goo.gl/4Ptzkf
If you need additional help with the Clean Install, watch this:
https://youtu.be/p-h3myRD51A