Debugging - finding the problem

[DCOLES]

I'm not too experienced at debugging so I could use some help:

Here's what's supposed to happen:
User opens database, Logon screen comes up automatically (on startup)
The year shows up on the logon screen (by default)
User selects section and unit and enters username, clicks command button to open main menu.
At the main menu the user chooses data entry to enter a new record.
The year shows up on the data entry screen (brought over from the logon screen)
The year is saved with a new record (saved by clicking a command button).
Everytime I open and test this database on my PC it works. (i.e. the year shows up on the logon and data entry screens and 'save' works)

Here's the problem:
One user opens the database on her PC but the year is not on the logon screen .. the field is blank. She can navigate to the data entry screen just fine.
She can enter all the fields required but when she tries to save it the year is missing so my user gets an error.
She can go back to the logon screen and put the year in the field but when she goes to the data entry screen the year is not there and if she checks it's still missing from the logon screen.
I can't recreate this problem on my own PC. I can blank out the year on the logon screen but it still comes up on the data entry screen (as it should) and will be there if I go back.
I had another user try to recreate it with another PC using the same choices but everything seems to be fine - it works like mine.

Additional information if it matters: the year is in a drop down box so the user can look at past years. It defaults to the current year when the logon screen is opened. (except in this case)

Any help on how to find out what's happening?

[johnhutchison]

The first place I would look is Missing References.
On the offending machine, open the db with the shift key down (so it does not attempt to load any form) then activate the VBA editor with Alt + F11.

Go to Tools References, and see if any of the ticked references say missing. If there are, you need to untick them, and replace them with something equivalent from the list of available references. Generally this means finding one with an earlier version number than the missing one.

Exit the editor, close and reopen the database.

Is your database split? with each user having their own copy of the front end? If not the references problem will keep coming back.