I've got a workbook with many sheets. One sheet has pivot tables on it and
one other has charts, charting data pulled from the pivot tables.

When I open the workbook I get three errors, one after the other, which say:
The PivotTable field name is not valid. To create a PivotTable report, you
must use data that is organized as a list with labeled columns. If you are
changing the name of a PivotTable field, you must type a new name for the
field.

That's all well and good but I'm not the only one who uses this workbook and
I don't know where these errors are coming from. Someone else changed
something and now I'm left with trying to figure out what happened. My
problem is that I don't know how to go about finding where these field names
are that need to be "changed back" or "re-written" or "fixed", and I'm
obviously not a brilliant enough Excel user to figure it out. Can anyone
please help with simple directions on how to resolve this issue?

Thanks in advance for any help!
Dax Arroway