This seems to be a recurring problem. I just assisted another person here
with similar problem (beta created files not opening). He sent me the file
as email attachment, I used Excel 2007 to open it and save back as regular
97-2007 .xls file and sent it back to him. Worked for him.

Remember, Beta is closed, Office/Excel 2007 is now a released product.

We can try the fix I did for the other person if you want: send as
attachments to email to (remove spaces)
HelpFrom @ jlathamsite.com

I suggest that you change the filename from .xlsx to almost anything else,
such as .xxx - it seems that Outlook 2007 considers .xlsx files to be
"potentially dangerous attachments" and wants to deny me access to them and
classify the whole deal as Junk Email. Go figure. Remind me in the email
what the original filenames were.

"Burger23" wrote:

I am using Office 2007 Beta 2 with the Technical redresh installed (
version 12.0.4407.1005). I am trying to open 2 files created in 05/06 and
saved in the .xlsx format. I am getting the following error message:

"The wordbook was created in an earlier beta version of Excel 2007, and it
cannot be opned in the current version of Excel. To open the workbook, you
must first open and save it in Excel 2007 Beta 2, and then you can opn it in
the current version of Excel."

Other xlsx workbooks created after this time open fine.

Ideas...