It is probably related to jDeli library.
OK, now that we have access to the actual images....
Without the jdeli library, jAlbum can't handle HEIC images at all. With that library, it can, but does a lot of heavy breathing - painfully slow. And the console errors show up as soon as you add the images to a project - no need to make an album at all.
At this point, HEIC is clearly a vintage that isn't ready for drinking, at least not in the jAlbum Wine Bar.