1. Cookies; Select Privacy. Under History, select Firefox will Use Custom Settings. Press the button on the right side called Show Cookies. Use the search bar to look for the site. Note; There may be more than one entry. ...
2. Cache; Select Advanced > Network. Across from Cached Web Content, Press Clear Now.
'No video with supported format and MIME type found' issue support.mozilla.org > en-US > questions
MP4 Videos Require a MIME Type on Your Server to Play Properly
1. Right-click the site in IIS and select Properties.
2. Select the HTTP Headers Tab.
3. Select File Types.
4. Under the MIME Map section, select New Type.
5. Type ". mp4" as the associated extension and "video/mpeg" as the content type.
6. Click OK.
MP4 Videos Require a MIME Type on Your Server to Play Properly articulate.com > support > article > mp4-videos-require-a-mime-type-on-yo...
This problem occurs when your browser lacks certain functionality that is required to play that video. ...
Video format or MIME type is not supported error in Firefox
www.thewindowsclub.com > video-format-mime-type-not-supported-error...
MIME type stands for multipurpose internet mail extensions and is a format for a video file that is transmitted across the internet. ... Today, a MIME type is not just for email, but are used by web browsers and web servers to understand what kind of files are being sent to them.
Correct MIME types for serving video files - Encoding.com Help
help.encoding.com > knowledge-base > article > correct-mime-types-for-se...