Will - I'm experiencing the same problem.  Installed the new Media Module <for DNN 6.> - already made host changes in webconfig to accommodate larger file sizes - and MP4 file types - was able to upload the MP4 using File Manager - but not Media Manager. <br /> <br /> Media Manager still tells me "File type mp4 is not valid in this context. Valid File Types Include: jpg,jpeg,jpe,gif,bmp,png,swf,.swf,.avi,.<br /> <br /> and the Chart that gets displayed clearly tells me that MP4 files are checked for module and site.    HELP<br /> <br /> <br /> <br /> <img alt="" /><img alt="" />