Hello,
This morning (7 am here) i tried to access learn tab links but they didn’t work and created only a grey effect on the left part of the launcher.
I got same result when i tried links from the news tab and links in the left part of the launcher.
It was a bug not related to the engine (certainly to windows 8 but maybe to google drive because i updated it yesterday to last version). I got same issue for other links and it 's ok after a restart.