So I saw someone reporting this before me, but you told him it's invalid because this is an issue on his computer and not on Minecraft itself, here I am to prove this is a bug with Minecraft by easy steps:

1. First proof is really simple, I know alot of players have this problem.
2. Second one is not a proof, I think this is the reason for this bug:

when you launch Minecraft, a file automatically is created in the logs folder, as I know, the type of file you are using for logs cost money, maybe what happens is that as I load Minecraft, the game is loading and I get a new GZ archive file, the file can't be opened but it must be created to open Minecraft, so the computer is trying to open Minecraft without the GZ file, I don't really know how minecraft launching works but I think replacing the file used to logs may fix the issue... I hope I'm correct...