One problem is that you have some number field or variable defined so it is
too small to handle an aggregated value.
Another is that sometimes you have a divided by a number very near zero and
the control or variable is sized wrong to handle that.
Another cause is that you are attempting to divide by zero and for some reason
are getting the overflow error instead of the divide by zero error.
If you have numbers defined as Integer type, try changing them to Long or
Double types.
Are you trying to sum an integer field in your report footer or a group
footer? If so, try changing the control's source to
=Sum(Cdbl(SomeField))
If the field can be null you may need something more complex, such as
=Sum(CDbl(IIF(IsNull(SomeField),0,SomeField)))
John Spencer
Access MVP 2002-2005, 2007-2009
The Hilltop Institute
University of Maryland Baltimore County