Quality Switching issues in Firefox

Hi Martin ,

I have a problem with quality switching on firefox (mac). When I play video, I can see the loader, the video wont load and I get black screen (instead video) but trigger “end video” is fired.

If I remove quality switching, video start correctly. If I’ll try with chrome on mac all it’s ok. This is a bug with firefox?

I noticed that when load page firefox show me this error

Il valore “video/mp4” specificato per l’attributo “type” non è supportato. Impossibile completare il caricamento della risorsa multimediale https://xxxx/0_sd.mp4?AWSAccessKeyId=AKIAJRFRDFKVB5M63U5A&Expires=1418867815&Signature=AYl3idcbJVz8nODnUzAR7MblOk0%3D. corso-fondamentale-google-analytics
Il valore “video/mp4” specificato per l’attributo “type” non è supportato. Impossibile completare il caricamento della risorsa multimediale https://xxx/0_ld.mp4?AWSAccessKeyId=AKIAJRFRDFKVB5M63U5A&Expires=1418867814&Signature=kk5H9bA9lto5PC5sDh5jmbGpdS4%3D. corso-fondamentale-google-analytics
Il valore “video/mp4” specificato per l’attributo “type” non è supportato. Impossibile completare il caricamento della risorsa multimediale https://xxx/0_hd.mp4?AWSAccessKeyId=AKIAJRFRDFKVB5M63U5A&Expires=1418867813&Signature=PULuZvhELS2dEovDi6DVvPZTjIc%3D.

This error is in italian but tell me that the video mp4 mimetype is not a supported mimetype and I think that firefox wont support mp4 but, why firefox try to download all 3 quality video?

Can you help me to fix this?

Thank you
David