Hi, In your filename don't use these characters. ? [ ] / \ = + < > ; : " , | *
Also do a repair permission on your hard drive. To do that go to applications-utilities-disk utility. Open disk utility and highlight your drive on the left hand side and click "repair disk permissions" (it may take 15-20 mins to complete). Hopefully one of those will solve your issue but if not let me know.
Thank you. That worked - I am now able to open the file, rename it, and open it again.
But can you explain a bit more about what the problem was and how to avoid it in future? I have had this kind of problem several times. Powerpoint for Mac does seem to behave in an unpredictable way when you make changes to files, especially renaming. Similar problems occur when I save files as .ppt (1997-2004) - I have learnt never to make changes once they are saved as .ppt, and have lost work on occasion.
If you can help me understand and avoid these problems in future it will be £32 well spent!
Great, I'm glad you are back to working. The file and folder name characters are generally allowed by Apple OS X but not allowed by Windows so some microsoft programs for mac get confused when they have them in their name because the programmers have not/could not allow for the differences between the two platforms. The permissions issue could affect any file/folder, it may occur because of another issue (such as file naming) or moving files into different folders which have different permissions that it may then take on (which you may or may not want) or they get corrupted for some other underlying reason and need repairing. Hope that helps explain it and if you need any other help in the future please let me know.
Thanks. Just went for lunch. It seems to be a permissions issue rather than a filenames issue, so a last question: Is there any way to avoid Powerpoint permissions getting corrupted so easily? Is there a safe renaming procedure, for example? Or a safe procedure for saving a Powerpoint file with a different name - perhaps by saving it in a different folder?
The permissions should not change that often. Create a new folder and make sure you have full read/write permissions to the folder. Put a test ppt file in it and rename it a few times to see what happens to the file permissions (they should not change). Don't save in a folder or subfolder with any of the unusual characters in it.
OK, many thanks. Very helpful.