I downloaded the software 'Perian' to help me see an MKV video file made on another software 'OBS'. I cannot see the file, it is a white sheet icon. Every time I go to install Perian, mac has a prompt message that says "Perian must be installed before you use it, do you want to install it now?" and will give me the choice to either install on the main account or all accounts. I click on the Perian icon, and a new message prompt comes up, "Perian.prefPane cannot be opened because the developer cannot be verified." I have researched how to bypass this message and apparently, the 'allow anything' choice on privacy and security doesn't work on Big Sur. (I haven't updated my mac to Monterey yet if that means anything.) Either way I do it, according to research, I get absolutely nowhere. Can I even download this, to begin with?