Windows 10 start menu critical error

I had a customer today who had upgraded to Windows 10 from Windows 7. All was going well until he rebooted and the Windows 10 start menu gave an error:

“Critical Error – Your Start menu isn’t working.  We’ll try to fix it the next time you sign in.”

Of course this was never fixed the next time they signed in, it was just kept reappearing.

Windows 10 start menu critical error fix

After much googling and hair pulling I found out the cause was dropbox. Once I uninstalled Dropbox, and rebooted, the menu started working.

I have restarted several time and the problem has not reappeared. So we have reinstalled Dropbox again and all seems to running well.

If this helps or you have a different resolution, please let me know,

Thanks

Ian