When you hit "File" then "Open" all files in current folder are shown (this is within paint.net program) They all have either an X or checkmark next to them.
When an X is marked by a file image and name, that file can no longer be modified (no changes are saved). How does a file get an X (in red) or a checkmark (in green)? I can no longer use any file marked with an X! PLEASE HELP1