Try to open math inspector on betalabs:
The following error appears on the console and the math function does not open up
Uncaught TypeError: Cannot call method 'getModel' of undefined VM2690:273
ve.ui.MWMathInspector.setup VM2690:273
(anonymous function) VM2688:23
proxy load.php?debug=false&lang=en&modules=jquery%2Cmediawiki%2CSpinner%7Cjquery.triggerQueueCallback%2Cl…:10
listenerWrapper VM2688:6
oo.EventEmitter.emit VM2688:7
(anonymous function) VM2688:20
pollExternalStylesheets
Version: unspecified
Severity: normal