Excel Password Protection Error

Some of our users on Excel 2007 (including myself) are receiving the error below when trying to password protect a .xlsx file. The error message does not appear when applying a password to a .xls file. After the password is "applied" the .xlsx file becomes corrupted and the error is shown "Excel cannot open the file 'FILENAME.xlsx' because the file format or file extension is not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file.". Please note that this only affects some Excel 2007 users and only applies to those affected users when placing a password on .xlsx files.

I have checked out the event logs and reinstalled Office 2007 without success. Does anyone know the answer?

Error message when applying a password to a .xlsx file

The document was saved successfully, but Excel cannot re-open it because of a sharing violation. Please close the document and try to open it again.

Steps to Reproduce:

1. Open Excel
2. Office Button | Save
3. Tools | General Options
4. Enter password in Password to open field | Click OK
5. Reenter password | Click OK
6. Click OK to save file
7. Error above is received.

Hi,
Does everybody have xl2007??

Hi,
Isn't a .xlsx file from xl2007 ?
Maybe you need to save the workbook as a 2003 version,
I don't use 2007 yet, but I know when you go to save as, change the file format to 2003 .
I think it's actually called 97-03 workbook, but you will find it, and if it's saved as .xls then everybody should be able to use it

Originally Posted by SunnySeattle

I should have mentioned in the original post that this is a problem only affecting some Office 2007 users. It only applies to password protecting Excel 2007 .xlsx files. The error does not occur using the same computer and Excel 2007 when password protecting a .xls file.

Does my previous answer not address that issue??
I hope if I bring this up somebody else may be able to reply!!!