When things that work on one computer don't work on another computer, the
first thing you have to think about is missing references. You need to check
for this. My guess would be that the custom function
Nulltozero()
references something in a library that's missing.
Here are Doug Steele's instructions on how to troubleshoot the problem:
*** Quote ***
Any time functions that previously worked suddenly don't, the first thing to
suspect is a references problem.
This can be caused by differences in either the location or file version of
certain files between the machine where the application was developed, and
where it's being run (or the file missing completely from the target machine).
Such differences are common when new software is installed.
On the machine(s) where it's not working, open any code module (or open the
Debug Window, using Ctrl-G, provided you haven't selected the "keep debug
window on top" option). Select Tools | References from the menu bar. Examine
all of the selected references.
If any of the selected references have "MISSING:" in front of them, unselect
them, and back out of the dialog. If you really need the reference(s) you
just unselected (you can tell by doing a Compile All Modules), go back in and
reselect them.
If none have "MISSING:", select an additional reference at random, back out
of the dialog, then go back in and unselect the reference you just added. If
that doesn't solve the problem, try to unselect as many of the selected
references as you can (Access may not let you unselect them all), back out of
the dialog, then go back in and reselect the references you just unselected.
(NOTE: write down what the references are before you delete them, because
they'll be in a different order when you go back in)
For far more than you could ever want to know about this problem, check out
http://www.accessmvp.com/djsteele/AccessReferenceErrors.html
Just so you know: the problem will occur even if the library that contains
the specific function that's failing doesn't have a problem.
**** End Quote ****
