When Avast updated recently to 23.3, it now causes a blank black screen when you open the Avast application. So, I uninstalled Avast, updated my video card, Nvidia GeForce video card, reinstalled Avast, but issue persists. So, I uninstalled Avast again. Installed AVG and issue with that antivirus is the same too, same black window when opening the application. Also, since AVG is owned by Avast, this is probably expected. So, I uninstalled AVG too. Currently using Windows Defender as my antivirus. I'm using Windows 10 Pro 64bit. I expect this issue is prevalent on lots of systems based on this forum thread. No problems with 23.2, but problems exist with 23.3. Don't know what your programmers did, but hopefully they get this issue resolved soon. You need to allow us to download the previous version of Avast, 23.2 until this issue is fixed.