Header Video Upload

Hi I have tried to upload a video but it will not load via the CatchTheme/Wordpress interface. Appearance => Customize => Header Media => Header Video => Upload Custom Video I have uploaded it via FTP but cannot find the file in the Media Library. It is located in the same folder as all the other images I use for my site: public_html > wp-content > uploads  The video is .mp4 format and recommended dimensions of 1920 × 1080 pixels. The file size is 450Mb. For now I am using the link to YouTube that is working but it slows down the loading of the video on the page and the YouTube bar at the top and logo at bottom are distracting. Is there a solution to uploading the video via the CatchTheme/Wordpress interface? Or how can I make the video that is uploaded via FTP appear in the Media Library? Thanks for your help! Julien