Under the Previous Versions tab there should be a 'File versions' section,
any previous versions of the file will be listed in there with the
date/time of the previous file version, and when you select the previous
version you'll have the Open, Copy, and Restore buttons available. You can
click Copy to keep the current version (one that's getting the error) or
Restore (to overwrite the current file version with the previous one).

If you don't have any previous versions in the list you might want to
contact support at 800-MICROSOFT or http://support.microsoft.com, but the
file's likely corrupt and hense not recoverable, so you may need to
recreate the file.


Best Regards,

Aaron Rykhus, Visio Support
Microsoft Corporation
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This posting is provided "AS IS" with no warranties, and confers no rights.