The most likely cause is that you have a problem with your References
collection. This is caused by the client workstation having different
versions of referenced libraries than on the machine where the application
was developed (or the libraries missing from the client machine)
While in the VB Editor, select Tools | References from the menu bar. Examine
all of the checked references (they'll be at the top of the list). If any of
them 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, under the Debug menu), 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)