If you sign into a Unity account using the launcher and then attempt to press the Open Project button, the button will do nothing.

Since this only occurs after signing in, you can work around the issue by closing the launcher and opening Unity again. If you are already singed in, the button will work.

Regression introduced in 2017.3.0b11

Tested on 2017.2.0f3, 2017.3.0b10, 2017.3.0b11

1. Install Unity
2. Open Unity
3. Make sure you are signed out of a Unity Account
4. Sign in
5. Select the Open Project button at the top right