Unity : AndroidVideoMedia Error, tracks not found ?

Hi !
I want to read 360° video tracks in an app made with Unity.
I have this error : "AndroiVideoMedia : no tracks in myFolder/myFile".
My app finds the right path. The error appears when I click on a button in my app to launch a video.
I use Unity 2019.3.15.
Can you help me to resolve my problem ?

Thanks a lot for answers !