Calibre will not open, Gdk-Warning, drawable is not a native X11 window

It’s been a while since I’ve used Calibre to manage my Kindle, but today I wanted to transfer some PDF’s.
Unfortunately Calibre stopped working as soon as I tried to open a dialog window.
As it seems, Fedora has adopted a new display server, called Wayland. Since Calibre has dependencies in the previous adoption X-Server, Calibre won’t start.
In my case, the solution was to set a different GDK backend, before starting Calibre.

Solution:

Open a terminal and enter the following command:

GDK_BACKEND=x11 calibre