I think I'm seeing something similar. I have a ShareLink with a string value and a Preview. If the user tries to save it to a file on iOS, it works fine. When I run the same on Mac (built for iPad, so not Mac Catalyst), I get a crash. All other options on the Share sheet works except Save to files. If I remove the preview, it removes the save to files option. I wonder if it something to do with sandbox access for Mac apps built for iPad?