Can't download updates / versions of Minecraft

Hi Mojang! I'm here to send you a bug about my Minecraft Launcher.

When i click on the Launch it opens, this is ok, but when i choose a minecraft Version (in that case i tryied with 1.8.8 but all versions are bugged) there it comes a bug with a list of "Repors about the bug" that should help me but i can't still fix this bug, this is the report =
"Nome: 1.11.json
URL: https://launchermeta.mojang.com/mc/assets/1.11/e264980ad255aad2174cbe4d674c102474ae5202/1.11.json
Dettagli dell'errore: Attempting to move successful download to C:/Users\PC\AppData\Roaming\.minecraft\assets\indexes/1.11.json Impossibile accedere al file. Il file � utilizzato da un altro processo
Nome file su disco: 4527-f47b-5b96-e2b4
Percorso: C:\Users\PC\AppData\Local\Temp\4527-f47b-5b96-e2b4
Esiste: file

And i can't just play Minecraft, every time i try to click on each single version of Minecraft, the Launcher starts the download of the version but after 2 seconds, it comes the report.

Steps to Reproduce:
1. Open the Launcher
2. Choose a version
3. Click on "Play" of that version
4. Appers the Report Window
5. The download stops.