This problem generally occurs when opening the file if:
- The document doesn't have full read and write permissions.
- The document is already open on a different machine.
- The document is corrupted.
Make sure you have full read and write access to the QuarkXPress file; whether it is saved on your desktop or on a server.
Confirm that the file is not open on any other computer. If it is open on another computer, close the QuarkXPress file and then try to open it again on the computer where the error message was received.
If the QuarkXPress file has full read and write permissions and you are still not able to open the file, then it might be possible the file is corrupted.
Note: If you are able to open the file but are not able to save it, then save as the file to different location or save the file with a different name.