Multiterm 2021 won't start

Hi, I bought 2021 Studio last year and just bought a new PC. I went to downloads and successfully downloaded Trados but I'm having problems with Muliterm.  I went through the Multiterm installation routine and icon is displayed on the deskttop and it won't start at all. When I click on Convert I get the  attached error message: An error occurred: could not load file or application "SDL.MultiTerm.Destktop.Platform ....version 16.0.0, Culture =neutral....

Also, MultiTerm has now mysteriously disappeared altogether from my downloads folder.

As always, I can't understand a word of the SDL error message but I would very much appreciate it if somebody could help with install MT because I'm supposed to be able to run it one two different devices.