system monitor shell extension won't start in Ubuntu 19.04: TypeError: this._construct is undefined

[Martin Vysny]

After upgrade to Ubuntu 19.04, the gnome-shell-extension-system-monitor no longer shows in the upper Gnome Shell panel. The `lg` tool shows only one line of error for the system monitor shell extension:

TypeError: this._construct is undefined

sudo journalctl /usr/bin/gnome-shell does not seem to contain anything useful except:

joulu 09 14:54:45 mavi-vaadin gnome-shell[3046]: Some code called array.toString() on a Uint8Array instance. Previously this would have interpreted the bytes of the array as a string, but that is nonstand
                                                 (Note that array.toString() may have been called implicitly.)
                                                 0 refresh/<() ["/<email address hidden>/extension.js":1991]
                                                 1 () ["self-hosted":979]

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: gnome-shell-extension-system-monitor 36-1
ProcVersionSignature: Ubuntu 5.0.0-7.8-generic 5.0.0
Uname: Linux 5.0.0-7-generic x86_64
ApportVersion: 2.20.10-0ubuntu23
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Wed Mar 13 16:44:48 2019
InstallationDate: Installed on 2016-09-05 (919 days ago)
InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
PackageArchitecture: all
SourcePackage: gnome-shell-extension-system-monitor
UpgradeStatus: Upgraded to disco on 2019-03-12 (1 days ago)

[Martin Vysny (vyzivus)]

Reported upstream as https://github.com/paradoxxxzero/gnome-shell-system-monitor-applet/issues/508

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.