Thank you for your welcome , am a long time user of Magix. Am sticking with Windows 7 and dedicated to my photography and movie editing. Qitw good Intel i7 -4790 CPU@3.6GHInt. Mem 8GB.
Had not not long ago updated to Movie Edit Pro Plus 2019 vs.19.0.1.23 and now to the same but but updated 2020 vs. 20.0.1.65 which appears in all respects and has sound but no picture in monitor or display in play. I have now reinstalled previous version which again works fine. But would still like to know problem appears a magix problem.
The other video editor I used stopped supporting Win7 in its current version because Win8.1 and up have a built-in audio codec that the editor now relies on. I have Win8.1 on my other box and like it. (After I put the old Start Menu back.) I call it "Windows 10 Lite" because it is like Win10, but without a lot of the garbage and without as much telemetry. (Which is easier to disable in Win8.1.) Also, Win8.1 is stable, in the sense that MS isn't changing it every 6 months.
Thank you for all your comments, I realise Win7 support has stopped and have Win10 on laptop for other major use. All otherwise works fine for me and am happy to stay with previous now reinstalled version of Movie Edit Pro plus 2019 and will look to reexamine update at future time.