Dear Adam:
Not a lot to go on. I suggest you break the query into separate
non-UNION SELECT queries and try each one. I think you'll find one or
more of them has this problem. Possibly you have some math that's
doing this in a calculated column. Remove calculated columns one at a
time to see which one it is. Replace the offending calculated column
with a set of columns that display the values used in the calculation.
Next, you'll need to look at these to see which set of values is
incalculable. Let us know what you find if you still need help.
Tom Ellison
Microsoft Access MVP
Ellison Enterprises - Your One Stop IT Experts
