Maybe some others here can give you that assurance. It's my understanding your v11 will open in v16. However if you have some type of FX added that was part of a third-party plugin you have with v11 and that is not present in v16, that part would not appear.

A test would be to download the trial version of Vegas Pro 16 and try it.

Note also that if you have third-party 32-bit plug-ins in v 11 they will only load into the 32-bit versions. The Sony Vegas Movie Studio 11 product line was 32-bit only. The Magix-branded Vegas Pro versions are 64-bit only.

I think I understand what you're all trying to tell me... I haven't really thought about what "extras" or "add-ons" I might be using... I do think I tried to add support for certain codecs some years back. Is there a way I can determine what specific "add-ons" I have now?

Keep Sony Vegas Movie Studio HD 11.0 Platinum on your machine. Both programs will co-exist on the same machine. If you find a problem with an old project in the future you can open it in the program that created it. People have been doing such things for decades. Search for IBM 1401 emulator.

Interesting that you would want assurances from a software company. I would rather deal with a used car salesperson. No one on this forum speaks for Magix.

Thanks John... yes, I know that forums are reliable/objective that company reps - I value the feedback you all have given me...