gsconnect fails to start (no module tweener found in path)

[Rod Miller]

Trying to install gnome-shell-extension-gsconnect on Ubuntu 20.04 resulted in GNOME crashing.
Upgraded to Ubuntu 21.04, then this message comes up (every time) in syslog on logging on:
gnome-shell[3026]: JS ERROR: Extension <email address hidden>: ImportError: No JS module 'tweener' found in search path
@/<email address hidden>/shell/tooltip.js:10:17
@/<email address hidden>/shell/gmenu.js:11:17
@/<email address hidden>/shell/device.js:12:15
@/<email address hidden>/extension.js:21:16
_callExtensionInit@resource:///org/gnome/shell/ui/extensionSystem.js:427:13
loadExtension@resource:///org/gnome/shell/ui/extensionSystem.js:348:27
_loadExtensions/<@resource:///org/gnome/shell/ui/extensionSystem.js:597:18
collectFromDatadirs@resource:///org/gnome/shell/misc/fileUtils.js:27:28
_loadExtensions@resource:///org/gnome/shell/ui/extensionSystem.js:572:19
_enableAllExtensions@resource:///org/gnome/shell/ui/extensionSystem.js:606:18
_sessionUpdated@resource:///org/gnome/shell/ui/extensionSystem.js:637:18
init@resource:///org/gnome/shell/ui/extensionSystem.js:57:14
_initializeUI@resource:///org/gnome/shell/ui/main.js:272:22
start@resource:///org/gnome/shell/ui/main.js:162:5
@<main>:1:47
#########Tried on another Ubuntu 21.04 computer: exactly same results
gnome-extensions enable <email address hidden> # State: ERROR after enable, on both computers

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: gnome-shell-extension-gsconnect 20-0ubuntu2
ProcVersionSignature: Ubuntu 5.11.0-34.36-generic 5.11.22
Uname: Linux 5.11.0-34-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.11-0ubuntu65.1
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Sun Sep 12 10:57:05 2021
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-shell-extension-gsconnect
UpgradeStatus: Upgraded to hirsute on 2021-09-05 (6 days ago)

[Erich Eickmeyer (eeickmeyer)]

This version of gsconnect doesn't actually work with Ubuntu 21.04 (which is also EOL). Marking as duplicate.