Linkedin Auth Example fails on popup validation

[stevewinni-cc]

Linkedin Auth Example fails on popup validation with https://us-central1-[projectid].cloudfunctions.net/token error 500

How to reproduce these conditions

Sample name or URL where you found the bug
Vanilla install of LinkedIn example script https://acf-framework.firebaseapp.com/

Failing Function code used (including require/import commands at the top)
When a user with the same email address exists in the system popup returns an error on;

ERROR 500 for resource;
https://us-central1-acf-framework.cloudfunctions.net/token?code=[the-code]&state=b756059fb917884aa05eff90d9927f8a47fa4c07&callback=tokenReceived net::ERR_ABORTED
(anonymous) @ popup.html?

Steps to set up and reproduce

Followed these steps here;

https://github.com/firebase/functions-samples/tree/master/linkedin-auth

Sample data pasted or attached as JSON (not an image)
{
"database": {
"rules": "database.rules.json"
},
"hosting": {
"public": "public"
}
}

Security rules used
{
"rules": {
"linkedInAccessToken": {
"$uid": {
".read": "auth.uid === $uid",
".write": "auth.uid === $uid"
}
}
}
}

Debug output

5:50:17.767 PM	warning	token	Error: The email address is already in use by another account. at FirebaseAuthError.Error (native) at FirebaseAuthError.FirebaseError [as constructor] (/user_code/node_modules/firebase-admin/lib/utils/error.js:25:28) at new FirebaseAuthError (/user_code/node_modules/firebase-admin/lib/utils/error.js:90:23) at Function.FirebaseAuthError.fromServerError (/user_code/node_modules/firebase-admin/lib/utils/error.js:114:16) at /user_code/node_modules/firebase-admin/lib/auth/auth-api-request.js:350:45 at process._tickDomainCallback (internal/process/next_tick.js:135:7)	more_vert

5:50:17.765 PM	warning	token	Unhandled rejection

Screenshots

Expected behavior

Should inform the user that email already in use and with what mechanism

Actual behavior

Popup. Blank screen with "Processing...." error in console.

[coluccini]

Same thing here ☝️