UPDATE 8/14/23
Bought a brand new external terabyte ssd yesterday and got the attached error this morning. I think I MAY have an answer but I can't find any tech on this. After 32 years (I started using it in 1992 for 'real') I know the basics so I search for deeper reasons past bad dev's being forced to meet a sprint and turning in crap.
Is it possible that using the same scratch disk for After Effects and Premier is what is causing issues? Even though I'm not 'using' AE or Premier, they are all set to the same dedicated scratch disk and thus have created their own folders as needed on the drive.
The proper thing would be to remove all folders except for Photoshop and test it but yee gods, surely someone actually *knows* whether or not it could be an issue? In 2023, disk access, especially with SSD shouldn't be still in testing phases but I can certainly understand how it could be.
And now, 4 hours later, I do not even have an external connected and have plenty of space on my root drive (about 950 megs) and the error popped up when just choosing "open".. didn't even get to select a file.
Something is causing PS to generate a false positive about scratch drives. Any ideas?