These questions come to mind:
- What operating system are you on?
- Does this happen with all files new blank file, existing ones?
- Does saving the file to a different place make any difference? - Saving to the desktop for example
For starters I would want to try restoring the Photoshop preferences to the defaults and test in a new user account
- Windows XP: Choose Start > Help And Support and see the article "Add a new user to the computer," or contact your system administrator.
- Windows Vista/Windows 7: Create new local administrator account (Windows Vista) (kb404912)
- Mac OS: Creating and modifying user accounts on the Apple support website.
I'll add my response to this question because we are having the same problem here. My partner and I are using Lion 10.8.1 with Photoshop CS5.5. We have 3.2 GHz 27" iMacs with 12 GB of RAM and 1TB drives.
Could not save as “[filname]” because of a program error.
We have only recently had this issue since upgrading to Lion as we've been using CS5.5 without issue for many months. When saving the files to our HD, we have no problem saving the file. When we open and re-save or save as back to our corporate server, we get this error. When we do this, the file disappears from the server. The only recourse is to save the file to our desktops and copy the file to the server. This issue is not present in inDesign or Illustrator files.
Correct me if I'm wrong, but isn't 10.8.1 actually Mountain Lion? I imagine everyone realizes that but I just want to make sure there's no confusion...
There is a workaround that's been discovered that minimizes problems with saving on a server: Go into your Photoshop - Preferences - File Handling dialog and turn off the saving of Image Previews.
To be clear, it's worked around the problem, and I hear it's not 100% reliable, so watch carefully for failures and save local copies of your work.
If I recall correctly, Adobe says it's most likely an OS bug with Mountain Lion and accessing servers. I think there's an OS tweak that can accomplish a similar thing but allow you to write thumbnail previews on your local drive, but I'll be darned if I can turn up that thread. Not being a Mac expert the name of the file has drained out of my feeble brain, so I don't have a specific thing to search for.