UI failed to load

Hello.
My OS version is Windows 10 Home 18.03 17134.48.
Today my Avast Free decided that it needs to update itself to version 18.4.2338.
After reboot it greeted me with “UI failed to load. This is really embarrassing.” Well, it sure is. The Remote Desktop Services solution doesn’t work. And I can’t perform Repair because it wants me to - quote: “Uninstall Windows Defender as it is incompatible with Avast.” despite it being turned off for the process of Repair.
WTF. I CAN’T uninstall Defender from Windows 10. And even if I could I certainly wouldn’t get rid of the one thing that works and protects my PC while Avast became an unresponsive garbage. I just wanted to say that as a long term user (been with Avast since 2006) I’m really disappointed. To this day I didn’t have any problems and I was quite pleased with it (despite SafeZone silently installing or strange add-ons being installed into Firefox, but I’d just delete them and move on until next product update). But such behaviour is simply unacceptable. If not for Defender my PC would be just sitting out there completely vulnerable. It’s sad to see what became of Avast in the last couple of years. It used be a simple and nice AV and now it’s filled with bugs and bloatware. I’m seriously considering to stop bothering with Avast and giving Defender a chance.

I,'m having the same problem. I got MS security update KB4103721 download and ever since then the Avast UI oops message appears. I uninstall the update and Avast UI starts. Also the Avast had just updated its program. What’s going on??

Follow instructions: https://forum.avast.com/index.php?topic=218193.msg1460463#msg1460463

https://support.avast.com/article/Troubleshoot-Antivirus-UI-Failed-load

Okay.
Seems like disabling hardware virtualiztion via Avast UI > Settings > Troubleshooting solved the problem (at least for now).
After Rebooting PC, Avast properly loaded and is working again.
But to think that such a serius bug would exist. I mean you had so much time to prepare for 1803 update. It would be somewhat acceptable in a beta version but on a finished product?