Apologies, didn't realize I should add that when posting and forgot to add it afterwards; to quote the thread I have about Premiere Pro:
I'm using the latest version of both premiere and after effects, I do not have another computer to test this on, it worked for *one* run on a separate user account on the same computer, then same errors on both programs, I've reinstalled these three times each now, and I am not going to reinstall windows before trying literally everything else.
Nvidia RTX 2080, Intel i7 9700K, 16GB RAM, 2.5TB total drive space, 4 partitions including C drive, 67GB free on C, >150GB free on all other partitions, Windows 10.
Every driver is updated, and the latest windows updates are installed too.
I was having the same issue running on windows 10. I found another post that suggested running in Windows 8 compatability mode. Its worked with no issues since!
just find the AfterFX.exe file (likely at, "C:\Program Files\Adobe\Adobe After Effects 2021\Support Files\AfterFX.exe") then right click the file, > Properties > "Compatability" Tab and check the box next to "Run this progam in compatability mode for:" and select Windows 8.
I have no idea why or how this works, but it fixed my issues opening After Effects, Audition and Illustrator. Hope this helps someone else!