Was trying to use Total Validator(v8.2.1) plugin with Firefox(v24.0) when Avast DeepScreen kicked in and apologized for the inconvenience, but Total Validator failed anyway.
On further attempts, DeepScreen didn't kick in, but Total Validator still failed.
However, Avast -> Settings -> Antivirus -> Exlusions -> DeepScreen tab now shows "C:\Program Files (x86)\TotalValidatorTool\TotalValidatorCL2.exe" in the list so I figured it checked out OK.
Restarted computer and Total Validator still fails. Temporarily disabled Avast using shields control and Total Validator worked. Re-enabling all shields kills Total Validator again.
Decided to exclude the process: Avast -> Settings -> Active Protection -> Web Shield Settings -> Exclusions: checked the Processes to exclude: box and clicked Add, but no dialog opens! I cannot add anything to this area.
So now I have to disable all shields whenever I run this plugin... unless someone has a solution.