I threw out the original FoxBox and created a new one being sure to check the box as mentioned. Same problem. In my TenFourFox app, I can play html5 no problem. I have the mp4 enabler and correct files in my library.
I cannot reproduce the problem. When I create a FoxBox for YT with all default settings it works just fine, playing VP9 per default (mp4 enabler is installed, but YT prefers web.m for Firefox; to get mp4 you need to disable web.m in the browser or FoxBox's prefs).
What's the video URL of the specific video you were trying to watch when making the screenshot you attached?
Try making a YT FoxBox with this URL as the start page:
https://www.youtube.com/html5 What does it say about the supported formats? (see screenshot for what I'm getting).
on 10 Jun, 2019 03:39 PM
Snapshot attached. You can see some formats indicate not supported.
I am using Feature Parity Release 9 (TenFourFox) and TenFourFoxBox
I do not find any place to "disable web.m" either in TenFourFox or FoxBox.
Some additional info:
Machine Name: Power Mac G5
Machine Model: PowerMac11,2
CPU Type: PowerPC G5 (1.1)
Number Of CPUs: 2
CPU Speed: 2 GHz
L2 Cache (per CPU): 1 MB
Memory: 8.5 GB
Bus Speed: 1 GHz
Boot ROM Version: 5.2.7f1
Serial Number: G86150G7UUY
Before we do anything else: Please close all FoxBoxes and update TFF to FPR 14. I still don't know why VP9 is disabled in your FoxBox, but H.264 cannot even work in FPR 9 technically regardless if it's disabled or not.