Smart Scan stage 3 hangs indefinitely

[blebnevus.avast]

New Avast user here.  Successfully installed and ran a deep scan.  But the final stage of a smart scan ("advanced issues") hangs forever at the 99% point -- and then doesn't even stop on command.  Any idea what might cause this and how to fix it?

[r@vast]

Hi,

Did you restart after the installation of AO? Do you have any other antivirus applications installed?
You can also try to repair Avast One. Account> Settings> Troubleshoot> "Repair Avast One"

[blebnevus.avast]

Thanks for your reply.  Yes, I did restart after installation - and then again when this problem showed up.  Didn't help.
I have no other third-party security programs.  Windows Defender automatically yields to Avast, I believe.
I wonder if any other users have experienced this problem.  I'd love to be able to address the cause directly rather than just hoping a general "repair" will solve it.

[Elliott Gill]

Hi blebnevus.avast.

I'm not sure what is causing this issue, but I've found a resolve.

I previously had Avast installed, and allowed the Avast One installer to upgrade / overwrite it. It was after I had done this when the smart scan began hanging up on stage 3 (83%).

I've just uninstalled Avast completely and done a fresh install from scratch. The smart scanner is working fine now. I’m guessing this issue occurs if you upgrade from Avast to Avast One.

I hope this helps.