Error loading extension on Ubuntu 18.04 / Gnome 3.28.2

[spencer-hann]

when I try to install I only get "Error loading extension"

sudo journalctl /usr/bin/gnome-shell | grep egg yields:

Sep 03 17:15:40 margaret gnome-shell[1806]: Some code accessed the property 'EggTimer' on the module 'eggtimer'. That property was defined with 'let' or 'const' inside the module. This was previously supported, but is not correct according to the ES6 standard. Any symbols to be exported from a module must be defined with 'var'. The property access will work as previously for the time being, but please fix your code anyway.
Sep 03 17:15:40 margaret gnome-shell[1806]: egg-timer [info ]: initializing
Sep 03 17:15:40 margaret gnome-shell[1806]: egg-timer [info ]: enabling
Sep 03 17:15:40 margaret gnome-shell[1806]: Extension "[email protected]" had error: TypeError: this.add_child is not a function

Ubuntu 18.04
Gnome 3.28.2

Thanks in advance

[gregorriegler]

Thank you for pointing that out.
I actually installed a VM with your specifications to reproduce and fix the issue.
I could fix the error you described, but after that it still doesn't work because of different errors.
This is taking too much time for me. So unless somebody is willing to provide me with a pull request, i will not support Ubuntu 18.04 for now. I apologize.