Hello
Plugin by Taapat works perfectly.
Plugin uses API key. If plugin doesn't work, you have to create your personal key and put it in file youtubeui.py ( usr/lib/python/extensions/YouTube/youtubeui.py)
I did my vide how to do it
I think it's not a god idea, to reboot with the power switch.
Or was it a coincidence that you touched the dreambox with your hand at the same time with the reboot ?