I’m honestly not sure, but I may have fixed this issue through fixing another issue I had in another post earlier this week involving file paths for images and masks 25, and there possibly being mismatches between raw images and their corresponding masks. Perhaps that was causing this indexing issue? At the very least, I haven’t had any crashes since I made those changes to ensure all images and masks are matched correctly on Linux (and Windows), and I haven’t been able to replicate it.