One of the computers is an iMac 2019 i5, the other an M1 Macbook Air, both running Monterey (due to some legacy software and the avoidance of subscriptions). Booted the iMac into Sequoia, reloaded 4.0.1 and now it crashes everytime I apply adjustments to the 3RF files when I click on another thumbnail. Restarting the software, the adjustments aren't all saved, and it repeats itself crashing every time I adjust and click on another thumbnail; maddening. Guess it's back to 3.x.x and working with 3F files