This is an age old question that people everywhere have tried to solve. I didn't notice it in this forum though. How do you prevent excel from crashing when you rename a worksheet if you have udfs. You'd figure by 2010 this would be solved, but it isn't.
There are a couple of specific settings relating to UDFs that can cause a problem.
Individually, none of the operations/commands are an issue, but when used in the same worksheet, they will cause an Excel crash with a
c0000005 exception.
Specifically, if you have a volatile function (your code function contains the "Application.Volatile (True)" tag), where you change the DisplayAlerts status (for example, "Application.DisplayAlerts = False"), then if you change the name of a worksheet within the workbook that contains a function with these two commands, Excel (up to 2010, not tested with 2013 yet) will crash.
It is possible to trigger this either by changing the sheet name in VBA code or within the interactive user session by clicking on the sheet tab and changing the name.
I am not sure if this is the cause of the problem that oaishm is having, given the lack of details, but it is one explanation of the symptom.
