Video doesn't start.

[MarlonAndradee]

As you can see in the image, the video doesn't start, there's only a black window appearing where the video should be.

I'm using: Firefox Quantum 60.0b11 (64-bit) and Youtube Center Developer version with greasemonkey.

[pingufetch5]

Getting the same thing here. Windows 7 Firefox Userscript.

[Orbilo]

same problem here. Using google chrome + Tampermonkey

[Coffeeist]

Yep, same issue here, using Vivaldi (Chrome version of the addon)

[NiGHTsC]

This just happent on me as well, Win7 64bit+FF55.0.3+YTCenter v548

Seriously hoping this is Youtube itself's issue and will be fixed ASAP, cause I don't think we are going to get any fix from YeP...

[Fallen10111]

I had this. It worked an hour ago when I got in from work. Went to watch a video now, not working. I disabled Youtube Center, worked fine. I think it's an update they've done youtubes end maybe.

[flakzilla]

Same issue, FF56 on linux w/ greasemonkey. Everything works normally if I turn off greasemonkey so it's definitely a problem with YTC. Apparently youtube won't let you restore the old layout either... this might be the end, lads. Save us @YePpHa!

[9aaron]

Same. Resetting YTC settings doesn't work either. Windows 10 64 bit, Chrome Version 66.0.3359.81 (Official Build) beta (64-bit), YTC 548.

[LamerGamer]

Had the same issue. Didn't work when installed through Chrome, but Tampermonkey worked, strangely.

[GuyB01]

Same as @LamerGamer - The Chrome extension's stopped working but the Violentmonkey script works.

[NiGHTsC]

Grease and Tamper both won't work on FF

[valarnin]

Quick fix is to change the way window.matchMedia is getting overridden.
I'm running one of the dev builds for Chrome, here's what I did:
There are two spots in YouTubeCenter.js where window.matchMedia gets set to null. This needs to be changed to instead set to a function that returns false.
For me, I changed line 11061 from:

          window.matchMedia = null;

to:

          window.matchMedia = function(){return false;};

And line 26853 from:

	  injectScript(function(){ window.matchMedia = null; }, "matchMediaOverride.js");

to:

	  injectScript(function(){ window.matchMedia = function(){return false;}; }, "matchMediaOverride.js");

[texaskelly]

Can confirm that valarnin's edit works.

Hopefully we get an official update to the script real soon, although given that there's seemingly been no development for months on this, I'm guessing we shouldn't hold our breaths.

[NiGHTsC]

@valarnin: Thank you Thank you!

YeP is working on new YT script, gonna take a while but he's on the new project.

[valarnin]

If I wasn't extremely sick and had the energy to do more than just watch YT, I'd format a proper PR or upload fixed builds or something. But I'll leave that to someone that's not currently hacking up their lungs.
For those who can manage to apply the fix themselves, enjoy.

[bhrgunatha]

@valarnin Get well soon and a big thank you - youtube is so unpleasant without YTC!

[MarlonAndradee]

Thank you so much, it worked!

[dertrance]

@valarnin Thank you so much for the edit, it worked flawlessly! Get well soon!

[ccrowles]

@valarnin The edit works on firefox too! Thank you so much!

[xadious]

Thanks @valarnin, fix worked for me too on Chrome.

[adnieman]

Can confirm valarnin's fix works in FF59 with ViolentMonkey.

[ericboehs]

Cloning the repo to make the change. Jesus! This thing is 1.5GBs! lol. No wonder no one's made a pull request yet.

Anyways, here's the pull request: #2482

[Deleted user]

Thanks for the fix from here as well.

[YePpHa]

@ericboehs the reason for this is because I was stupid and didn't add the dist folder to the .gitignore file.