When creating a new question, please specify:

• What triggers the error?
• When this error is triggered?
• Is there any case this problem does not happen?
• If there's any VBA code involved, what's the code line that it happens?
• It only applies to Excel 2007? Have you tried in Excel XP / 2003?
• It only happens on your PC or anyone's?

Without this information, is almost impossible help you solving your problem.

Googling for this error message, I could suggest you to try to save the workbook in an older Excel version (say XP, 2003) and try to reopen it.

Rgds

I suggest you to try to save the workbook in an older Excel version (say XP, 2003) and try to reopen it.