Components not showing thumbnails in Pinegrow's library


I am new with Pinegrow and I am dealing with a lot of problems making it work properly.
I will be posting them one by one.
The first one is my components panel. I am trying to choose some of the resources, but all of them are just text with no class or image related.

I am opening a new project in BS4, and they look like the picture I am loading here.

Help will be appreciated.