I has follow your guidance by updating ionic-angular to version 3.6.1. Same error message still showing up on my default browser (firefox) and Chrome in incognito mode. => https://prnt.sc/h255lu
I has clearing all browser cache but error still appear.
Different result when i use chrome, this error not showing up when i use chrome in standard mode but another error appear when i trying to access quiz like this screen capture => https://prnt.sc/h25699