emulator runs fine but app shows white screen, error is below

Good day to all.

I'm following the teacher's notes and am ready to run the app in android studio 3.6.1. The emulator runs fine but when I open the app I get a white screen. At the bottom of the android windows, I see the following error.

Emulator: emulator: INFO: QtLogger.cpp:68: Critical: Uncaught TypeError: Cannot read property 'update' of undefined (qrc:/html/js/location-mock-web-channel.js:130, (null))

I have searched this website and google for the problem. I'm trying to figure out if this is a coding problem or something to do with android studio.

what I tried is in this link... emulator problems

Any help to understand the problem would be appreciated.

I eventually reinstalled android and started the project again only to find that the possible solution was to enable usb debugging on the phone. To do this you go to settings - click on about phone - click version number several times to enable developer mode. Then go back 1 step and click on developer mode. Enable usb debugging.

I think this could have fixed the problem so if you having a similar problem to me, please try this.