Cannot read properties of undefined (reading 'observe') error in JS console when recording a test

WebHome?language=en&…false&defer=false:2 Uncaught TypeError: Cannot read properties of undefined (reading 'observe')
    at HTMLDocument.<anonymous> (WebHome?language=en&…se&defer=false:2:40)
    at HTMLDocument.<anonymous> (prototype.js?r=1:7282:15)
    at fireEvent_DOM (prototype.js?r=1:7141:13)
    at fire (prototype.js?r=1:7130:17)
    at k (eventsBridge.js:61:26)
    at HTMLDocument._methodized [as fire] (prototype.js?r=1:456:23)
    at klass.displayRows (livetable.js:318:18)
    at onSuccess (livetable.js:240:16)
    at klass.respondToReadyState (prototype.js?r=1:1812:37)
    at klass.onStateChange (prototype.js?r=1:1754:12)
(anonymous)	@	WebHome?language=en&…false&defer=false:2
(anonymous)	@	prototype.js?r=1:7282
fireEvent_DOM	@	prototype.js?r=1:7141
fire	@	prototype.js?r=1:7130
k	@	eventsBridge.js:61
_methodized	@	prototype.js?r=1:456
displayRows	@	livetable.js:318
onSuccess	@	livetable.js:240
respondToReadyState	@	prototype.js?r=1:1812
onStateChange	@	prototype.js?r=1:1754
XMLHttpRequest.send		
request	@	prototype.js?r=1:1739
initialize	@	prototype.js?r=1:1704
(anonymous)	@	prototype.js?r=1:447
klass	@	prototype.js?r=1:80
k	@	livetable.js:199
getRows	@	livetable.js:256
showRows	@	livetable.js:493
initialize	@	livetable.js:140
klass	@	prototype.js?r=1:80
D	@	livetable.js:1403
(anonymous)	@	livetable.js:1425
u	@	livetable.js:1422
(anonymous)	@	prototype.js?r=1:7282
fireEvent_DOM	@	prototype.js?r=1:7141
fire	@	prototype.js?r=1:7130
k	@	eventsBridge.js:61
_methodized	@	prototype.js?r=1:456
initialize	@	xwiki.js:526
(anonymous)	@	prototype.js?r=1:7282
fireEvent_DOM	@	prototype.js?r=1:7141
fire	@	prototype.js?r=1:7130
k	@	eventsBridge.js:61
_methodized	@	prototype.js?r=1:456
fireContentLoadedEvent	@	prototype.js?r=1:7317