Youtube is not a good source for help with repairing Vegas issues. It rarely works out and there are a ton of people with no idea what they are talking about trying to give advice.

+ 100 😉

Thank you fr0sty and j-v :) very much appreciate you taking the time to respond. I've disabled the Quadro graphics card in the device manager and the computer seems to be working fine without it. I also installed the latest NVIDIA studio drivers for both cards yesterday as part of my troubleshooting efforts, so that's two suggestions checked off the list. I've got to take the dog for a walk and then I'll try some editing this afternoon to see if the stability improves. Your comments about 8 and 32-bit colour, and HDR are a little beyond my understanding, but I'll try to look up those settings and configure them as you've suggested. Thanks again, I'll report back and let you know how things go. Fingers crossed.

If it's beyond your understanding, you don't have a need for it yet. The main thing is you must start with 10 bit or higher video to even need any of that stuff, and then you must be targeting a TV that can display 10 bit or higher, which most cannot. Otherwise, keep your Vegas project settings at 8 bit at all times, do not use 32 bit mode.

"I've got to take the dog for a walk..."

You've got the important things covered already.

Regarding the 10-bit colour, my Panasonic GH-5 can record in 10-bit colour, so I was planning to record in 10 bit, edit and grade the footage, and then export in 8-bit colour. But if my RTX 2070 graphics card can now handle 10-bits of colour with the new drivers installed then that's a non-issue. So that's that problem solved.

Re. the stability of Vegas (the bigger issue) I just rendered a little sequence in After Effects and tried to import the uncompressed .avi file into Vegas, which I've done before with no problems, but when I tried it this time (via the import media function) it immediately crashed. When I tried again by dragging and dropping the same file straight onto the timeline it was okay. Things have gotten buggy, I fix one problem and another one materialises (especially since deleting the temporary files folder as per one of the troubleshooting suggestions on another thread).

I may try a re-install. I'm determined to get it working one way or another because I find it so much more intuitive and user friendly than the main alternative - Premier Pro. Thanks again for the suggestions and support, I'll report back when I've tinkered some more to give some closure to this micro drama :)

Did it crash or hang? There's a difference... many times, a hang will recover if given enough time. Still not what you want to have happen, obviously.

As for 10 bit color, I'm not sure if Vegas can still utilize the extra bit depth in 8 bit mode or not, someone else may be able to chime in on that one, but keep in mind that if you must enable 32 bit mode to grade your 10 bit color, performance is going to drop significantly (so make the switch after you're done editing), and because 32 bit changes everything about the way gamma is mapped, etc... your video is going to look different and may need some adjustments or the proper view transform applied to make it work with 8 bit output.

I'd set the project up this way, open it up 32 bit full range, right click on your GH5 clips, and select "vlog/vgamut" (this assumes you are recording using the VLOG-L picture profile in the GH5, which must be added on separately unless you have a GH5s, but it is highly recommended you shoot this way because it captures the max amount of dynamic range your camera can capture) under the color space settings. This should properly map the colors so that you get the most out of your 8 bit export and the video looks correct when previewing it in Vegas. Alternately, you can leave your GH5 footage (again, this relies on you shooting in VLOG-L mode) as-is, and use a VLOG to Rec709 conversion LUT (panasonic has some on their website, and there are others you can score for free as well, just do a google search for it) and then apply that LUT to the input side of your color grading panel, or add the LUT filter effect to any track your GH5 video is on and apply the LUT there instead, so it applies to the entire track at once.

@Sam-Ray Your where saying that when you render an uncompressed .AVI in AE, this will immediately crash Vegas? Have you already tried rendering an uncompressed .AVI in Vegas? And try to import this in to Vegas? Uncompressed .AVI is the most elementary kind of video material, so it would be very strange if Vegas crash on it. Does the file crash in (for example) Windows Media Player? Reinstalling Vegas is always a good idea by the way.