Suspect programme blocking

Hi,New user so not sure if this is the right section to ask this.I allowed a downloaded utility to open normally.It’s shown in the sandbox exclusion list.Is there a way to rescind this exclusion so that Avast will block it.Utility worked fine for a week and the started crashing.Uninstall from control panel fails,so I’m suspicious.Utility is fastest free You tube Down loader.

Remove it from the AutoSandbox, Settings, Files that will be excluded from automatic sandboxing; select the entry and you will then see a Delete button to remove the exclusion, see image.