"Automation error Unknown error" when my Excel file w. macros is opened on SOME computers

Dear forum members:

Unfortunately I have an - for me - very urgent problem. I recently revised a very long macro and put it online. Now I got mails from users stating that they receive an "Automation error Unknown error" message once they open the Excel file. Unfortunately, I cannot reproduce this problem directly on any of my computers - it works flawlessly here. On the net, I have only found some information that this error may be related to security updates KB2687441 (in Office 2007) or KB2597986 (in Office 2010).

The Excel file consists of many tables with VBA code, so I cannot post the complete macros here. Do you have a tip on how I could go to the source of the problem - maybe Excel puts an insightful log file somewhere, so that I can reproduce such a problem on my own machine in order to troubleshoot it?

So far, I have tried the following: On my computer, I renamed the registry key
HKCR\typelib\{831FDD16-0C5C-11D2-A9FC-0000F8754DA1}\2.0
to " 2.1" and added a new empty key "2.0". After this, I am getting this error message. With KB2687503 I can fix the error. But: How do I know if that is the problem for the other users? I would hate to let them test things stupidly.

Cheers,
Hlina

Hi Tsjallie:

Thanks for the link, it is another interesting approach to the problem with the security update MS has messed up. However, what I wonder is, how can I found out whether this is the reason my user's problem. They are usually in enterprises and do not have access to the registry or the permission to manually run updates or administrative tasks.

Hi Tsjallie:

I think it is a great idea to contact the support engineer - I really think, the user might have a supporting IT department. I will write an e-mail to the user tomorrow suggesting this solution.

Thanks! Hlina