Excel changing my workbook name to an invalid name

[bjw210]

I'm trying to link to a workbook but the when I click in the workbook I want to link to, Excel changes the name.

Name should read as
='[Example workbook.xlsm]Example Sheet'!A1

but instead, it changes it to read as below

='[Example workbook...m]Example Sheet'!A1

It says "The name that you entered is not valid."

This doesn't happen with any other workbook and it's causing huge issues.
I can type in the name and it'll link, but when I have to refresh the links Excel once again replaces the (xls) with (...).

Any ideas?

Advanced User
Using excel 2013 64 bit version

Thanks