Is there any way that I can get a copy of that document? I'd love to be able to pass it along to the Excel team so that they can figure out what went wrong. PM me for my email address.
It may be that you have too many decimal points in the name.
"All.done.on.a.mac. "
I think the naming of the document should not contain any decimal points - because it confuses the program opening the document. Usually the decimal point is what separates the name of the document from the extension.
I don't think the OP saved the file with that name, just that his point that the entire file was created and edited with a Mac.
My question to the OP is did you use/create any custom number formats? I know that shouldn't matter, but the error refers specifically to number formatting as the culprit.
I think the naming of the document should not contain any decimal points - because it confuses the program opening the document. Usually the decimal point is what separates the name of the document from the extension.