Hi Thank you for your question. So that we can look into this further, please can you confirm: * The software version of Fire TV that your device has? (From the Fire TV home screen, select '''Settings''', '''My Fire TV''' and you should the '''Software version''' Fire OS ???) * The version of Firefox you have installed? (From the Fire TV home screen, select '''Settings''', '''Applications''', '''Manage Installed Applications''', scroll down to (but do not select) Firefox and you should see the version number). * An example of a video you are trying to watch. With this information we should be able to find a solution for you.