Recent minor updates for WordPress introduced a couple of regressions when uploading audio and video files: On WordPress 4.3.x and earlier branches, audio/video files cannot be uploaded at all due to a fatal error. Full list of affected versions: 3.7.19, 3.8.19, 3.9.17, 4.0.16, 4.1.16, 4.2.13, 4.3.9. This will be fixed in the next minor update, see the Trac ticket #40085. On WordPress 4.4.x and later branches, audio/video files are uploaded with corrupted thumbnails. Full list of affected versions: 4.4.8, 4.5.7, 4.6.4, 4.7.3. This will be fixed in the next minor update, see the Trac ticket #40075. In the meantime, this plugin is a workaround that solves both issues and restores the upload functionality for audio and video files. Don’t forget to remove the plugin once the next minor WordPress update is available!