I have the same problem as described above.
Laucher updated itself and it doesn't work anymore…
It just exits instantly with code 0 without showing any dialog messages.
To reproduce, run cmd.exe as an administrator.
Go to %appdata% with: cd %appdata%
Use: mklink /D .minecraft "D:\.minecraft"
Optionally create folder on that path (mkdir?).
Make fresh install of launcher… and it won't work.
Please fix it, because I am unable to play. :C
Setting symbolic link and changing environment variable is are differnet issuses.
You are cruel bastards... I am "glad" that issues are intended...