youtube not playing firefox videos playback error

Hi when ever i play a YouTube video it pops up with this message here is a attachment

Start by disabling your addons and see what happens

nope tried to disable add-ones but nothing still the same if i reboot laptop i will try it then to see if is fixed

nope still doesn't work i think one of my addons is playing up but i don't know which i have restarted Firefox using about:support and then it works but the next time i load Firefox it comes up with the message help me

anyone please bump

it's working now strange