If you’re having trouble setting up your authenticator:
Change your default internet browser - done.
Ensure you are using the Battle.net Mobile App (the Battle.net Authenticator App is no longer supported) - Confirmed
Close any apps running in the background
Check your device’s internet connection
Make sure you have enough free space on your device - Sound fair, i did this.
Try detaching your Authenticator and reattaching it - impossible, everything results in - oops, something went wrong
Uninstall the Battle.net Mobile App, restart your phone, then reinstall the Battle.net Mobile App - done
Clear the Battle.net Mobile App’s Data and Cache from your device’s app manager, restart the app, and try again - Done
Clear the Battle.net Mobile App’s Data and Cache from your device’s app manager, restart the app, and try again - Cleared data + cache + restart phone + reinstalled app
I open the app and log in, → Oops something went wrong → click on authenticator → oops, something went wrong, click on anything? → Hmm, something went wrong.