The Desktop App’s Lock & Open / Save & Unlock feature for controlled editing and updates requires that each user’s computer have an application capable of both opening and saving the file being used, and keeping the original file’s type (extension).

A common issue arises when a file created with newer versions of Excel (an “.XLSX” file) needs to be edited by another use who lacks a newer version of Excel, or doesn’t even have Excel.

One way to solve the problem is to have the original file saved in the older “.XLS” format, even when using a newer version of Excel.

Another way to solve this for users lacking Excel (or the newest Excel) is to use LibreOffice 4.1 or later, which can both open and then save in “.XLSX” format. LibreOffice is a free, open source program similar to OpenOffice. OpenOffice 4.1, however, can only open an “.XLSX” file, but cannot then save updates in that format. OpenOffice may add this feature in a future release.