There can be a few reasons you can't save a CL file.
* For your situation, you might have a bad installation of Creo. It might have gotten corrupted, perhaps due to installation of another program or during its own installation.
* A tricky problem I've had in the past is if the directory I'm trying to save to has a very long name, Creo can't handle it. I don't know exactly what the character limit is, but people in my company have gotten in the habit of naming directories with, effectively, sentences, and it makes NC file writing fail. I've gotten around this by having a C:\ptc\NCfiles directory I save all my NC code stuff to.
* You might be using a student version of Creo, or some other restricted installation. These versions let you do all you want to learn the program, but don't let you output anything that could be used to manufacture parts. Or at least that's my understanding of it. From what I've seen you need to have a commercial license. I've never used a student version, so I don't know what kind of errors it throws at you when you attempt "forbidden" actions.
Hope one of these is your problem, though the last one could be tough to accept.
