The (terrible) doc/ppt/xls Microsoft Office document formats all have the same MIME type. This causes a lot of grief when using MediaWiki, as MediaWiki checks MIME types against file extensions for security purposes. In this article I’ll describe how to allow uploading for these file types, and how to get around the “The file is corrupt or has an incorrect extension” problem.
Allow doc/ppt/xls to be uploaded
Add the following lines to your LocalSettings.php to allow these formats: