When clicking on the launcher it goes to the 1.7.4 game window, that disappears, then the launcher reappears. In the Development Console tab it reports a Fatal error outside of the Java Runtime Environment. I have attached a text file of the contents of that tab.

Please note that I last used the game when we were at 1.6.4... Took a bit of time off... Today was the first attempt after downloading the new launcher.