Vlk, the problems persists:
1. If the Linux session is being closed - both in root and user account - and avast GUI is opened, next login with show the message Deleted stale lock file '/home/root/.vast/lockfile-root or Deleted stale lock file '/home/<user>/.vast/lockfile-<user>
2. Scanning is halted (GUI cannot be closed, scanning could not be stopped, pause button is not working) both in root and user account as described before.
3. Update works perfectly both in root and user account.