I have old Cubase 8 and 11. In the matter of upgrading a OSX system I chose do it from High Sierra to Catalina. One thing that I did not expected is that importing and playing video is not available in old Cubase…I have 11 why do I use 8? For many reasons about stability, performance and my sophisticated scripts in Keyboard maestro are set up with old Cubase.
I found one way to get back video without creating damn virtual OSX. Unfortunately you cannot use old video player anymore (you can put videoengine.bundle from C11xxx.app/Contents/Components/ to C8 and use import video feature again :), but video player is not showing)
I use VidPlayVST and it is pretty damn good for video. I will continue in searching for re-able video player for Cubase <10.