I installed Parallels software on Big Sur beta 6 and needed to go into this pane in order to Allow the publisher to be trusted and run. Great. Go in and get this error message. The final fix for me...was unplugging every single peripheral from the laptop. I use a USB hub, power goes through it, USB mouse, etc.
Don't ask me why, but unplugging the device (USB hub) so nothing was attached whatsoever, did the trick. As soon as I unplugged it, I was able to load the preference pane and allow the Parallels software to run.
I only tried it based on their kb article I found on their site, but I cannot publish it here.
Give it a shot and see if it helps.