Minecraft Version not downloading/updating

Put the summary of the bug you're having here

What I expected to happen was...:
What I expected to happen was that the minecraft launcher would automatically download and update minecraft version 1.9.

What actually happened was...:
Nothing. Literally nothing. Whenever I click Play button, it prompts downloading then after around 5 seconds. the Play button is clickable again and nothing happened. It did not download the v1.9.

Steps to Reproduce:
1. Open Minecraft Launcher
2. Click Play
3. Tadaah! nothing happens.