Automation Error 440 when Opening Userform

One of my clients reports that a project tracking file I created for them (years ago) is now giving a runtime error 440 (Automation error) when they try to add a new project.

The file has two userforms: NewProjectForm (for adding a new project) and EditProjectForm (for editing an existing project).
The runtime error occurs when executing the NewProjectForm.Show command. That userform has a UserForm_Initialize routine that initializes several comboboxes, checkboxes, and textboxes. The userform is never displayed; the error occurs before the form is displayed.
They have tried the file on at least two different PCs in their office - same result on each.

I am puzzled by two things:
-- The file works perfectly fine (no errors) on my PC, and has worked fine for them for years (until about a week ago, apparently).
-- The EditProjectForm ALSO has a UserForm_Initialize routine that initializes several comboboxes, checkboxes, and textboxes, but THAT userform works fine for them (no errors).

Can anyone suggest how to troubleshoot this? What could have changed in their system to cause this Automation error? Why would one userform crash, but the other one works OK?

Originally Posted by rorya

Get them to change their Error Trapping options in the VB Editor (Tools - Options - General tab) to 'Break in class module' then run the code again. It should then stop on the actual problem line in the Initialize event.

Nope, it still stops at the NewProjectForm.Show command. Same as before.

Originally Posted by rorya

When it stops there, if they press f8 what happens?

Same message: Error 440, Automation error

Has the name of the hyperlinking page been changed in the code section?

Have there been any changes to the Office version?

Is there any chance we can see the file?

Originally Posted by ibutun09

Has the name of the hyperlinking page been changed in the code section?

Have there been any changes to the Office version?

Is there any chance we can see the file?

There is no "hyperlinking page". Macro is triggered by a SelectionChange event on one of the worksheets, which (if they click on a certain cell) calls another macro (which is in a module). That macro consists of one line of code (NewProjectForm.Show), which is what triggers the error.

I suspect they may have gotten some kind of Office update, but I'm not sure.

Also, another interesting note: I sent them a copy of the original file that I created (2 years ago), and THAT file works OK for them, despite the userform and macro code being identical.

Sorry, I cannot share the actual file.

Originally Posted by rorya

If the original file works for them, it would suggest that they have changed something fundamental in their copy of the file, such as adding activex controls (which become part of the project).

If they changed anything significant, it was unintentional.
Looks like we'll be copying all their current data and pasting into the original file, to see if that fixes the issue.