Hey, unfortunately I don't have much time right now to give all the needed detail information (Arnold log etc) but I wanted to make you aware of an issue (maybe that's already a known problem) I have noticed while recording longer video tutorials (due to covid) for a course I am giving. I've recorded a short video. Arnold 4.0.4.1.
https://www.youtube.com/watch?v=j1q5Msd9qRw
In short: A (not too complicated) asset renders fine on RTX 2080 and 1080 machines (8GB), and the IPR can always be closed an restarted without problems (part 1 of the video labeled computer 1). This is true for 4 machines with either RTX 2080 or GTX 1080).
Now we do have two new machines with RTX 3090s, which I was using for the tutorial (it's a TeamViewer connection for all machines, so the recording is not interfering with anything here). Once you close the IPR and then reopen it again, arnold will exit with an Out of Device Memory (the asset clearly fits into the 24 GB if it renders fine on 8GB cards ;)) That's the computer 2 part. This was actually tested on two machines, same behavior. After that, Maya will hard crash if you open the IPR again, which, as you know ;) it always does once Arnold had a GPU error and you try that.
(As a note: The thin filme warning comes from a thin film node that is used in the CPU setup of that file. The node is not actually evaluated as it's connected to an AI switch which currently just reads a noise as a GPU alternative. The texture warning just comes from the fact that UDIM tile 1005 doesn't exist, although I don't know why it has to warn about that. 1001-1004 exist. I expect there to be not relation to the error on the 3090 but still thought I'd mention it.)
I'm sorry I can't post a log right now because I need to finish a few things here. You will most likely ask if we would update to 4.1.0 (reverted back to 4.0.4.1 because of another issue), which I'd gladly test out if I could! Unfortunately, I need those machines for rendering over night, and I can't update them right now, because I'd have to roll back to 4.0.4.1 since that's what all other machines currently use, and you can't have 4.1.0 and 4.0.4.1 render the same asset at the same time from the same Maya project on a network drive, as the older arnold versions will randomly loose their textures on some frames when doing so (I assume that is because of the changes to the .tx files / texture memory in 4.1.0) . Not an issue – just noticed it and that's basically the reason I unfortunately can't run some test you might ask me to.
I still hope that is enough information for now to investigate the issue, if its not an already known problem in either 4.0.4.1 or already fixed in newer versions.
Thanks and cheers,
Lennart