LunaticS0UL

Just spitballing: this could happen if you're using FAT, which has a maximum file size of 4gb. The file starts to save, but can only save the first 4gb, so the file gets chopped off at 4gb. Is it possible the file starts off under this limit, then grows after you make some edits? Otherwise Affinity shouldn't even let you save it to begin with... In my mind these symptoms point to a hard drive issue.