Since you mention your browser and ad blocker, I'm assuming you are trying to watch the Heathers movie on therokuchannel.com.
It plays okay here using Firefox as my browser.
Can you play other videos from therokuchannel.com?
Roku Community Streaming Expert
I am not a Roku employee, only a user like you. Please, no support questions via private message -- post them publicly to the Community where others may benefit as well.
If this post solves your problem please help others find this answer by clicking "Accept as Solution.".
Ultra 4800 | Streaming Stick 4K+ 3821 | TCL Roku TV 43S245/C107X
