Well I recently got an android box. I splurged and got the cheap M8S off of Amazon for $80. Seems like not the best option at the moment...but hopefully someone can help!
It came preinstalled with kitkat 4.4.2 and lots of addons including Kodi 15.2. Most of the addons with Kodi I am having great difficulty with. I have not been able to find a single stream on Genesis, phoenix, or 1 channel to work. Says check log, no streams available.
And also, YouTube only allows the quality to be a max of 360p. Wtf. I tried the app and using chrome to go to youtube.com, same issue.
At least I have been able to access my pc, which was my main reason for purchasing this device... But still, xbmc has a lot of content supposedly available that I have yet to access! Help.
I'm seeing the m8s on amazon going for just under $50US right now so idk if they're on sale atm or you just got a bad deal but with the amount of trouble you're having I'd say return the item and invest in a nexus player or an Nvidia shield TV both are reasonably priced.
The problem you're really running into is the box you purchased is a cash grab by companies who preinstall and setup already free software on an underpowered Android box running an unoptimized older version of the AndroidOS. Now unfortunately this sub is dedicated to AndroidTV (which is a separate fork of Android built with TVs in mind) so you won't find much help or knowledge about the specific problems you're running into. I would find out if maybe there is a dedicated forum on the web for your box with a user base more capable of helping you sort out the YouTube and KODI issues or try out /r/minipcs and see if you don't have better luck there.
Quick edit: look into the Kangaroo MiniPC if OS isn't an issue. It could be a $99US Windows solution that you'd have no issues with setting up KODI or YouTube. Good luck!