Excel file path limit
It's well known that Windows Explorer has 255 character limit for any file path. (See the Tip of the Night for October 10, 2015 on how to deal with this problem.) What's not so well know is that Microsoft imposes a limit of 218 characters for Excel files. See this post on the Microsoft Support site. Microsoft saves the additional space for worksheet names which may run up to 31 characters, 4 characters for a cell references, and an additional 2 brackets to denote the workbook name.