I'm not sure if you are still around, but I just found out youtube made a new update recently about his UI. You can click on your profile icon on the top right and press "Restore Classic Youtube". Who knows if that's going to fix your problem.
Do you have AdBlock on? If that's the case, pause or disable it and refresh the page. I also had black screen from youtube just like you a few mins ago and Adblock was the culprit.
I already did that part a long time ago but I don't have alot of time because I have to go at school but why don't you take a look on this tutorial: http://www.youtube.com/watch?v=xO5-Zj5k5QI...feature=related
It will probally help you who knows. All I remember is at the end, you just have to...
I can confirm that this does indeed work on my R4. Thank you very much WarioN64 for your tutorial . For those who are stuck at this part 14.) Run r4.bat. This will produce "R4_custom_English.zip", It's probally because you got the wrong ysmenu3270000 file from a torrent or something like...