It seems that you are using Excel 2007 and the worksheet is created in Excel
2003. When you open the file it may take some time as it is a huge file and
Excel 2007 takes more time to open the file.

When it is opened you will see a message along with a button near the
formula bar. click on this button and then click on "Enable This content"
radio button and then click OK.

Hope this will solve your problem.

Regards
Avi

"Nat" wrote:

I have a large document and it now says up the top compatibility mode. It
won't let me type, save or anything. The spreadsheet is rather large but it
only suddenly did this today.
Any ideas or help?