Ubuntu 18.04: Workspaces to Dock extension ERROR

Anyone else has problems with the 'Workspaces to Dock' extension in Ubuntu 18.04? I can install it with no problem from:

https://extensions.gnome.org/extension/427/workspaces-to-dock/

But every time I reboot, it does not load, and I see a warning sign in the GNOME Tweaks with the following message:

Error loading extension

Any clue?

EDIT:

Running the following command, as suggested in the comments, I spotted the following lines, which might be relevant.

sudo journalctl /usr/bin/gnome-shell | grep workspaces

Dec 24 13:41:35 dcarbajo-SLIMBOOK gnome-shell[2246]: Extension "[email protected]" had error: TypeError: Me is null
Dec 24 13:41:35 dcarbajo-SLIMBOOK gnome-shell[2246]: Extension [email protected] already installed in /home/dcarbajo/.local/share/gnome-shell/extensions/[email protected]. /usr/share/gnome-shell/extensions/[email protected] will not be loaded