Google XLSX formated files don't import into FM13

Issue report by Justin Close

Product

FileMaker Pro

Version

13.0v5

Operating system version

OS X 10.9.5

Description of the issue

When trying to import an XLSX file that was created by Google Sheets, FileMaker throws an error messaging saying that the file type isn't supported. Here's another thread on this issue: http://forums.filemaker.com/posts/86080d05a8

Steps to reproduce the problem

Go to Google Sheets
Create a new sheet
Type in some text (optional)
Download file as XLSX
Try to open file in FM 13

Expected result

XLSX file would get imported into FM table/fields

Actual result

FileMaker throws an error message

Exact text of any error message(s) that appear

The selected Excel workbook has an unsupported file format. Please convert the workbook to the Excel 2007, or Excel 2008 file format and try again.

Workaround

Open the file in Excel, save the file (no changes need to be made before saving), try and open again and it is happy.