I have used these functions several times in the past, but when I tried to use Neural Restore - Raw Denoise this morning, it said the module is not loaded. After that, the Process button was grayed out and unselectable. All of the other Neural Restore Process buttons are also disabled.
I went to darktable settings, and the AI modules still show as Downloaded and Enabled. I tried to Download/Update selected, but that had no effect.
What has happened?
Oh, I also noticed yesterday that the AI masking was not working. At that time, I was simply puzzled and went on about my business.
So, to report what it is doing, I re-attempted it just now. When I try to do a drawn mask and click the AI button, it responds “object mask preparation failed”.
I had an idea, and I disabled the entire AI section, restarted darktable, and enabled AI, again. It did not help. 
Dear Tim, I have no knowledge of this subject, so probably of no help.
Did something change on you computer that might have caused this? And if so are you able to revert on that change?
My settings look like this. Is your ONNX Runt lib still detected?
Hope someone with more knowledge will chime in.
Well, I run Arch Linux, so a few things are changing day by day.
As far as I recall, ONNX has never been installed, and all of my AI modules were working at some time in the past. Maybe I just don’t remember it. If ONNX is needed, I will look for it.
Arch has quite a few packages for ONNX. Maybe the one I need is onnxruntime-cuda.
I am now 100% certain that I have never installed anything like that before.
OK, it looks like the problem is solved (by installing onnxruntime-cuda), at least for raw denoise. Thanks very much, @Jetze
Notes: That package and its dependencies are huge - well more than 3 GB
Raw denoise now runs very fast. It used to take around 30 seconds or more; on my first sample, it took about 5 seconds.
