Around a month ago, my system (Windows 10) downloaded a Windows Update and had to restart in order to install it. After the restart, I got a black screen only with the Comodo widget visible. No task bar, no icons, nothing. When I tried to load a service, it would say not available or sth like that and the only way to open msconfig was through the command prompt.
After some troubleshooting, I found out that the bug was caused by Secure Shopping. When I chose to boot in safe mode and uninstall it, Windows loaded with no problems and no black screens. Today, I tried to re-install CIS and accidently installed Secure Shopping again. Guess what? The black screen is back!!! Uninstalled with the same procedure and all is running fine again.
Make sure you are using latest CIS v6294 then delete the CSS installers found in both C:\ProgramData\Comodo Downloader\cis\download\installs\5050\xml_binaries\css and C:\ProgramData\Comodo\Installer if they exist. Then run the secure shopping task to download the fixed version.