Excel VBA Error: Automation error - the object invoked has disconnected from its clie

I have a rather complicated insurance rating application for D&O, EPL and fiduciary rating - there's a main user form that shields users from the underlying Excel worksheets - there are numerous worksheets storing tables of data and that contain numerous excel functions. In between the worksheets and the UI is about 8,000 lines of VBA code.

The application runs fine on my laptop, but when I release it for users to test, the application blows up immediately with the error message indicated in the title.

I've checked versioning of software, service pack installed, add-ins, options, settings, etc. and cannot determine why/how my laptop is setup differently from users. I have also tried running this application on another developers laptop - same problem as with users.

On my computer I have discovered that under Options, Add-ins, several are listed under the "Disabled application Add-ins" heading instead of under "Disabled Application Add-ins". Thes einclude "Analysis Toolpack", Analysis Toolpack - VBA", "Conditional Sum Wizard", Internet Assistant VBA", Lookup Wizard" and "Solver Add-in". Could this be what's causing the behavioral difference?

I'd be very grateful for any help anyone could provide.

Thanks

Thanks for the response.

There are thousands of references to moving data into, out of or between ranges across multiple worksheets and UI objects. When I've made statement sytnax errors, I'd get compile errors that highlighted the offending statement. What do you mean by an "not completely explicitly referenced"? Would an statement example be something like:

txtName = "George"

opposed to

txtName.Value = "George"

Does the above example illustrate the concept?

I too, am now getting the error. When I shut down my computer for the day and booted up later at home, I started getting the error.

I'm pretty certain the error is occurring on the form load event, which fires when the workbook is opened. I can't get past it. Is there a way to open the workbook up in a mode that bypasses the firing of the workbook open code? I earlier versions of MS Office I'd open the app while pressing the shift key, I think (it's been a while since I've needed to do that).

Thanks for your help.