It is NOT a duplicate, since the fix you suggest does not work (not for me and not for a friend I referred to this 'solution' for the same problem), nor did any other fix or solution I found in the forum and online before I filed my report here.
Please reopen and fix the new launcher troubles.
Oke, tried this yesterday. Didn't work!
Still can not launch Minecraft in any version, with any launcher.
Please fix this - even better, roll back this great new launcher, that is causing so much problems for so many people!
Like I said: I already tried that and it doesn't solve the problem.
Besides that, on the other two pc's in my house, those of my sons, with their own, completely different configuration as mine, Minecraft can also not be started since the introduction of your socalled improved launcher!
Furthermore I have heard from 3 different friends that they have the same problem.
So you see, this problem is not ours to fix, it is Mojangs' to fix, so please fix it as soon as possible!