Numbers crashes when I try to open .xls
I have a workbook that was handed down to me that I have been using in Excel 2008 for Mac. Very simple. 4 pages, no fancy functions. I have it saved in DropBox as a .xls file. Every time I try to open it in Numbers, it crashes. I'm using Mavericks. What can I do? Thanks in advance!
MacBook Pro (13-inch Mid 2012), OS X Mavericks (10.9.2)