We’ve had a couple of customers ask about this recently, where documents created in newer versions of MS Office don’t download to the browser correctly. Instead of downloading as an MS Office document they download as a ZIP file.
The reason behind this is because they are new file types and are basically XML files inside a ZIP archive and servers setup before these new files came on the scene don’t know what the correct type of file is, so they check the file and it looks like a ZIP archive, so that’s what they tell your browser.
All of our cPanel based business class hosting fully supports the new MS Office MIME Types – so your files will download as MS Office documents and not as ZIP archive files.
If you’d like to modify your own server so that it supports the new MS Office file extensions and file types then you need to place the following entries in to you /etc/mime.types file (for plain CentOS/RedHat) or /usr/local/apache/conf/mime.types if you’re running cPanel.
application/vnd.ms-word.document.macroEnabled.12 .docm application/vnd.openxmlformats-officedocument.wordprocessingml.document .docx application/vnd.ms-word.template.macroEnabled.12 .dotm application/vnd.openxmlformats-officedocument.wordprocessingml.template .dotx application/vnd.ms-powerpoint.slideshow.macroEnabled.12 .ppsm application/vnd.openxmlformats-officedocument.presentationml.slideshow .ppsx application/vnd.ms-powerpoint.presentation.macroEnabled.12 .pptm application/vnd.openxmlformats-officedocument.presentationml.presentation .pptx application/vnd.ms-excel.sheet.binary.macroEnabled.12 .xlsb application/vnd.ms-excel.sheet.macroEnabled.12 .xlsm application/vnd.openxmlformats-officedocument.spreadsheetml.sheet .xlsx application/vnd.ms-xpsdocument .xps application/vnd.ms-powerpoint.template.macroEnabled.12 .potm application/vnd.openxmlformats-officedocument.presentationml.template .potx application/vnd.ms-powerpoint.addin.macroEnabled.12 .ppam application/vnd.ms-powerpoint.presentation.macroEnabled.12 .pptm application/vnd.ms-excel.addin.macroEnabled.12 .xlam application/vnd.ms-excel.sheet.binary.macroEnabled.12 .xlsb application/vnd.ms-excel.template.macroEnabled.12 .xltm application/vnd.openxmlformats-officedocument.spreadsheetml .xltx
Once done, restart Apache and you should be good to go with MS Office Files downloading correctly.