Avast shutdown by another program

I had Avast antivirus free edition installed on our local office file server for evaluation for the last 3 months. Just recently, it has an “X” and says it is being shut down by another program. This server rarely access the Internet. So I uninstall Avast, use the “cleaner” tool provided and reinstall latest version and same issue. Uninstall again, and build a rescue disk(this was a tedious task in itself) from a know working computer. No virus found. Enable Windows Defender, and do a full scan, no virus found. So I’m left wondering what’s going on with Avast?

1]
avast free is not designed to run on a server

2]
https://forum.avast.com/index.php?topic=189221.0