When i opened the launcher and clicked "Play", it wanted to download the version again (1.11.2), and it did that every time, so i deleted MC and installed it again. Still the same problem.

Name: 1.10.jar
URL: https://launcher.mojang.com/mc/game/1.10/client/ba038efbc6d9e4a046927a7658413d0276895739/client.jar
Error details: UNKNOWN/-354
Filename on disk: 8fd9-3181-0914-9205
Path: C:\Users\MyName\AppData\Local\Temp\8fd9-3181-0914-9205
Exists: file

I'm sorry if there's not enough information or if this has been reported before.