Xltx File Extension
Xltx extension is related to Microsoft Excel templates. You can try to open xltx files with Excel 2007 or upper versions.
Xltx and xltm extensions stand for template files. These file formats are created by Microsoft Excel 2007-2015 software. If you need to open xltx files on your computer, you should install Office package. Or, you can try to open these files with Office kind of free softwares which you can easily download via internet.
What needed to Open Xltx file extensions.
Excel 2007 and upper versions
Links about Xltx file extension
No connection related to Xltx extension.