[Resolved] RIDER 2020.02.04 - Rider doesn't autocomplete anything from Unity

First of all, my versions:

- Rider 2020.02.04.

- Unity 2020.1.15f1

- Windows 10 x64 20H2

When I try to write something like: 

this.transform.Translate( 0, 0, 1 );

Only the 'this' keyword gets the tooltip to autocomplete it. I have installed Rider with (as far as I know) everything the installer asked me if I wanted to install, that includes the Unity plugin.

What I did was to create a new script in Unity, double clic it to open it with Rider (because Rider was the default IDE to open those files I have asssigned to Unity), it opened Rider with the content of the file correctly, and when I tried to write, I couldn't get the autocompletion tooltip to work.

Any ideas of what I am doing wrong?