It looks like the report is looking for some-thing that is not on the report.
Check the control source of the report to see if the data you want is actually there or not.
e.g
Lets say the reports control source is a query.
This query has 3 fields
[1]
[2]
=Sum[1]+[2]
if the field [1] is missing, the report can't do the calculation and ask with a parameter, "What is the value of field [1] ?"
Dave
