Built a rack as a generative demonstration. Works fine for me. No good for other folk when I upload it. This has never been a problem before!
My install seems fine, everything in the default folders etc.
So I made a simpler rack to post as a test, and a simplest one - all use Base and Primes. Two versions of each, one saved to the default location, one saved explicitly to a different drive.
Can folks please try to load these and post the results. Thanks :)