Sometine i found the worksheet menu Edit - Links helpful, but not very often.
Last time I had this type problem I deleted everything in the worksheet and
still had tthe error. The worksheet was corrupted. I did a binary search on
the .xls file a found the link, but there was no data in the workbook. Good
Luck. I simply copied every worksheet to a new workbook one at a time and
the error disappeared.

"Laurence Lombard" wrote:

When I close this workbook I get the message "Your formula contains an
invalid external reference to a worksheet. Verify the path, workbook, and
range name or cell reference are correct and try again". The error does not
seem to cause a critiacal problem. It gives no indication where the problem
is. How do I go about finding the problem formula.

Thanks
Laurence