Launcher crashes either at startup of launcher, or after hitting "Play"

With the new release of the launcher, it simply stopped working reliably.

Either the launcher crashes when started, or it crashed when loading the game itself. In the former case, the error message is simply "Launcher stopped working."

In the latter case, the log windows stays blank (see attached screenshot). The laucher does create a log in .minecraft (attached).

When the laucher itself starts, sometimes the game does start after choosing "Play". I have no clue why it sometimes does start. I can't find any pattern.

Sometimes the launcher crashes after hitting "Play". When I then proceed to kill the launcher process in win7, sometimes the game does start.

Tried reinstalling Minecraft and Java. Does not make any difference.

Hope you can help me out.