I had this problem once, and there is a very strange solution (if you haven't found one already). To start, pin minecraft to the taskbar so you can launch it easliy. When you try to open it, that dialogue box should pop up. Without even closing the dialogue box, open minecraft again. The same box should pop up. Just spam minecraft, and after about 2 dozen times, the game should open. Now just close all those dialogue boxes.
Weird, that actually worked. I'm using hexxit, from the technic launcher
Can you still download java 6 even though there java 7? plz reply
This thread is getting cluttered with more people replying with their own, separate issues. The error can happen because of a multitude of factors. Hence, please create your own thread about your own issues, and be sure to provide relevant logs for diagnosis.