Pivot Table Error
 

I have a pivot table that I based off of MS Access. I'm getting the
following error today that I have not had in the past. The error says
"[Microsoft][ODBC Microsoft Access Driver] Invalid character value for cast
on column number 12 (%Comp By Op)". First, I'm not sure what this error is,
and 2 not sure how to fix. Any insight to this would be appreciated. This
has run rock solid for the last year.

thanks,
Robert