I sent a spreadsheet with pivot table to client via email, and she got above
error. After investigation, we discovered that when she saves the file, the
name of the file gets changed to look like a copy - so SO Master.xls becomes
SO Master[1].xls. If she manually changes the name back to what it was when
it was sent, it works. She uses comcast.net mail. I guess it is somehow
saving the file at the server, and is giving her the copy on her computer.

I realize this isn't an excel issue.... but don't know where to ask - or how
to ask - how to change settings (in comcast?) so when she saves file, it
saves the file - not a copy. Just in case someone is familiar with this, I'd
love some assistance. Thank you.