From Magix support I got the following suggestion/solution and that seems to work for my crash on when cliking on "Make Video and then: Advanced Properties"). For my crash on startup, after loading a 'big project' I altered Dynamic Ram to 0 in Preferences/Video)

In Vegas or Movie Studio, this error occurs when Microsoft .NET Framework 3.5 Service Pack 1 (3.5.1) is either turned off or not installed properly on the system.

To resolve this issue, go to Control Panel -> Programs (Programs and Features) -> Turn Windows features on or off and scroll down the list to find Microsoft .NET Framework 3.5.1.

Turn on this feature by clicking the checkbox so it is filled. After allowing Windows to work through applying this feature, restart your system.
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(I activated two packages contained in the above : "microsoft communication Foundation (non-) http activation " )

Well I also suffered this same Exception - though it happened the instant that I clicked on the new "Style Transfer". All other OFX's worked fine.

It seems to relate to use of Intel QSV. If I turn this off, then not only will this exception stop, but the preview window starts working (it had stopped - even with Vegas 17). I have been updating to the latest Intel HD Graphics 520 [it is just a basic laptop!] - but it seems that there is something in Vegas that it really does not like! Driver ver 27.20.100.8581.

I tried the Dynamic RAM setting and the .Net Framework 3.5.1 afterwards, just to see if that lets me use the Intel GPU - but no, just the same. All very confusing, but at least I can get it working so I can experience the nice new features in 18. Just a shame I cant speed up rendering with the Intel GPU.

Any clue to solve this problem? I'm thinking in change to another software because it's very frustrating:
 

1. I added an empty video track.

2. I deleted the track above.

3. Sometimes Rendering works. 😰

@gonzalo-m4778
Have you tested the solutions above? - if so, what exactly was the result?

@es-l
Is that a question or a solution?

@es-l, @gonzalo-m4778
If you are looking for a solution, open your own thread and use the following structure to describe how exactly your problems are stored, what hardware and software you have and - most importantly - which media files you work with. Starts with B and C:
https://www.vegascreativesoftware.info/de/forum/important-information-required-to-help-you--110457/

1. I added an empty video track.

2. I deleted the track above.

3. Sometimes Rendering works. 😰

This is a kind of solution.