Follow-up Comment #6, bug #20917 (project relax): Ok, I can now see the problem. I didn't look at the attached image closely enough (https://gna.org/bugs/download.php?file_id=18116). The problem is that you cannot output a file in MS Windows with a colon in the name! I thought that that might be a problem on some systems. I think I will have to modify the spin ID string to remove the '#:@' characters before converting it into the file name. As an aside, the spin ID notation was contributed by Chris MacRaild (https://gna.org/users/macraild). The best way might be to replace each of these characters with an underscore '_'. As the spin IDs must be unique, this will still support all molecular systems (organic molecules, polymers, RNA/DNA, and proteins). _______________________________________________________ Reply to this item at: <http://gna.org/bugs/?20917> _______________________________________________ Message sent via/by Gna! http://gna.org/