I used to use this plug in on a previous Mac OS and was very happy with it (that's why I have avoided a one star rating). However, while downloading it to run with Firefox on Mac OSX Big Sur, I have hit a brick wall. A companion app is requested but the OS states that it is out of date and cannot be checked for malware. Attempts to circumvent this security barrier have failed, the companion app won't run and thus Video Download Helper is dead in the water.