Not really without you providing more information. Which videos don’t work? What happens - do you get an error message? What have you tried so far? Do you have any extensions? What device are you on? etc etc.
It’s not possible to help properly just from “videos don’t play” and nothing more.
With nothing more to go on I’d suggest a fresh install. Remove the app entirely from your device, redownload it and don’t install any extensions or even sign in. Retest, and if the problem is fixed then slowly begin to reconstruct your old setup one step at a time, retesting as you go.
Not really without you providing more information. Which videos don’t work? What happens - do you get an error message? What have you tried so far? Do you have any extensions? What device are you on? etc etc.
It’s not possible to help properly just from “videos don’t play” and nothing more.
With nothing more to go on I’d suggest a fresh install. Remove the app entirely from your device, redownload it and don’t install any extensions or even sign in. Retest, and if the problem is fixed then slowly begin to reconstruct your old setup one step at a time, retesting as you go.