What graphics card are you using?

In VP 18 when you click on help/driver update, what shows? Are you on the latest Pro/Enterprise driver? If not, download and install it.

I have downloaded and installed the AMD Radeon R9 270 (Adrenaline 2020 Edition 21.3.2) driver about three times now and it still shows up under the Driver Updates in Vegas. I had previously downloaded the 21.3.1 driver and that one is no longer showing in the Updates. There's also a 21.Q1.1 driver showing that I have downloaded and installed multiple times. I have also updated my AMD Radeon software directly from the AMD updater. In fact, that's when the problem with Vegas 18 started because I had AMD GPU acceleration prior to that update.

Could you share a screenshot of that driver update? If current version and online version are the same it's fine.

Perhaps uninstall the AMD updater- I got rid of NVIDIA GeForce Experience so I could keep control of the process.

The Radeon dashboard is showing that I have the update 21.3.2 which is the same driver version that Vegas keep telling me to install.

Under "preferred software version" what are the choices?

Anyway I noticed that this card says it only has 2GB of ram available. Vegas requires 4GB+. I looked it up and it's from 2013. In general Vegas supports cards for about 6 years, so this is just too old. (Your CPU is also 4th generation and Vegas wants gen 6+).

Minimum requirements here: https://www.vegascreativesoftware.com/us/vegas-pro/specifications/

AMD/ATI® Radeon with 4GB and VCE 3.0 or higher (Radeon Pro series with 8GB for HDR and 32 bit projects)

You could try rolling back the driver to what you were using when it worked. If you can get the GPU to once again work I wouldn't make any further driver changes, or upgrade Vegas to 19 until you have a new system.

Okay, I'll look into that. Thanks for the info. At least my 17 still has the GPU acceleration. I guess I could maybe roll 18 back to the original installation. Much appreciated.

I have no knowing about AMD, but something looks wrong here.
Outside Vegas is another driverversions installed than inside Vegas.
It looks like you have unabled that AMD GPU somewhere inside Vegas.
The only places to do that are Options/Video and Options/File I/O

Try go internal settings and search for So4compoundplug and changed the value to 0, I tried this last time and it works. But I'm using NVIDIA. not sure if it work the same for AMD

I have no knowing about AMD, but something looks wrong here.
Outside Vegas is another driverversions installed than inside Vegas.
It looks like you have unabled that AMD GPU somewhere inside Vegas.
The only places to do that are Options/Video and Options/File I/O

In 17 the File I/O preferences give me choices of Intel, Nvidia and AMD, but in 18 now the options are Off and Auto (Off). As was mentioned above, it appears the latest update has now made my current system too old, so I will either have to revert back to the previous version of 18, use 17 to render with GPU acceleration, or bite the bullet and get a new computer.

The minimum specs for 18 haven't changed since it was introduced, so I think a driver incompatibility is more likely the problem here? I used to have to use hacked drivers to get Vegas to find my AMD card (2012 era computer) and if I dared update it would disappear.

ctrl + shift
Now open the shortcut and initialize it.

t is preferable to hold down ctrl+shift and open the application to initialize it, as the data may still be there after uninstalling it!

That's called resetting. (Uninstalling/reinstalling doesn't clear the cache.)