Can you insert a worksheet in the workbook before you send it?

If you cannot, maybe it's because you have the workbook protected.

Tools|Protection|unprotect workbook
(you may need to supply a password)

If you can, then it's not the workbook protection.

Maybe something bad is happening to the workbook in the email. Can you try
zipping the file, then sending that?

jgraves wrote:

Can someone help me understand why, when I email a workbook to someone else,
they receive the workbook, but when they try to insert a new worksheet to it,
they get an odd error message and they cannot do it. I am sure this has
something to do with the protection of my workbook, but I can't figure it out.

--

Dave Peterson