The stub cannot run installer/updater executable (code 0x3)

Hello,
I’m having problems with Avast. It doesn’t work, I can’t uninstall it, I can’t re-install it or fix the installation - each time the errors message is “The stub cannot run installer/updater executable (code 0x3)”
I already tried using avastclear.exe and geek uninstaller (both in safe mode and with avast self-protection disabled) and the result is still the same: “The stub cannot run installer/updater executable (code 0x3)”

Please help. I attach FRST log files.