I just bought Minecraft and downloaded it. When I opened the launcher after logging in, it started downloading, but then just before it finished the download it disappeared and this error popped up:
I tried deleting the launcher, the .minecraft folder, and then re-downloading it but it didn't work either.
Best Answer
This means that Minecraft was not correctly installed.
Essentially, the launcher could not find one the files needed for Minecraft. Check if your profile is set to a valid Minecraft version, or that the Minecraft version jar is a valid one. You can also try and select a different Minecraft version and see if that works. If it does, it probably means that the jar file you want to use is corrupted. In that case, try and delete the version jar file and relaunch the game.