Since that extension is not active on E.G.O. any longer, I would first assume you manually installed it, and perhaps the installation was corrupted somehow.
I first suggest to remove it by running the following
sudo rm -R .firstname.lastname@example.org
If this doesn't work it was probably somehow installed system wide, so try
sudo rm -R /usr/share/gnome-shell/extensions/autohidetopbar2\@werewolves.us/
and then possibly try to reinstall it, you may need to first restart the shell though, so either logout and login, restart your system, or do Alt+F2, r and Enter
To reinstall it, basically you should just right click it and extract it, then the easy way is to keep this folder open and do the following.
Now run Alt+F2 and paste
~/.local/share/gnome-shell/extensions using Ctrl+v or by right click, paste.
Then either right click and copy the extension directory "extension_folder@domain", this directory is the one that contains the extension.js and metadata.json, now paste it into the other folder
~/.local/share/gnome-shell/extensions or just drag it there.
Next you have to restart the shell by running Alt+F2, r and Enter and it should be available. Once I know the details of the extension I can provide alternate instructions, but this is the easiest way.