2 days ago I started to get this error, everytime I opened the Launcher the Update Notes screen wasn't loading and I started to get the Play Offline button. I could "normally" open the game and join Servers, but since yesterday I couldn't.
I don't really know what's happening...
This is my Launcher log: http://pastebin.com/mCa1wN9g
If you need anything else please contact me.
Sorry for any grammar mistakes, English is not my main language.