Unable to save any further data or formatting to workbook. Each time I try to
save I get the following message:

Excel could not save all the data and formatting you recently added

To return to your workbook without saving click Cancel
If you want to continue saving changes without repairing the problem, click
OK.

When I click on help there is no message

Did you resolve the issue?

I'm having the same problem. I've searched the web and the closest I've got to a solution is that conditional formatting must be limited to 2050 rows. This doesn't seem to adequately answer the issue as I have other spreadsheets with a lot more conditional formatting rows that 2050.

I found that it is saves ok if I save the file as an earlier version of Excel. Not sure why this seems to work.

First create a Blank document in 97-2003 format. Then copy the sheet in 2007 format and paste it in the document created in 97 - 2003 format.

This will now retain the formating