Meteor works in Chrome but not in Firefox and IE


there is something strange going on. My client side works perfectly in chrome, but not in firefox or Edge. in these browsers I get this error.

I am only doing a isAlive test: I try if I can make a rest get call to external API. (getStreams), if I get an answer back, I now the other system is ALIVE. So if I make the call server side and no error, then I present a succes message:

Template.layout.onRendered(function() {
  // const instance = this;
  // instance.connection = new ReactiveVar();
  console.log('UI HELPER: Check if we have a connection to Sense?');'getStreams', (error, result) => {
    if (error) {      
      Session.set('NoSenseConnection', true);
      sAlert.error("We can't connect to Qlik Sense, is sense running, virtual proxy configured?");
    } else {
      var message = "Connected to Qlik Sense via the REST API's, we have tested this by requesting the list of streams via the QRS REST API."; 
      Session.set('NoSenseConnection', false);

the server side

export function getStreams() {    
    try {          
        const result = HTTP.get('http://' + + '/' + senseConfig.virtualProxy + '/qrs/stream/full', {
            headers: authHeaders,
            params: { 'xrfkey': senseConfig.xrfkey }            
    } catch (err) {
        throw new Meteor.Error('getStreams failed', err.message);

The error I only get in firefox and IE: (could it be that they can’t handle the arrow function, or that it times out to quick?)

Setup generic helper functions, for functions every template needs app.js:819:5
mutating the [[Prototype]] of an object will cause your code to run very slowly; instead create the object with the correct initial [[Prototype]] value using Object.create modules.js:21461:3
UI HELPER: Check if we have a connection to Sense? app.js:1249:3
client generation helper: get app table, the config used to generate the URLs to Sense:  Object { host: "2008ENT", port: 80, virtualProxyClientUsage: "meteor", UDC: "2008ENT" } app.js:969:13
Object { stack: "Meteor.makeErrorType/errorClass@htt…", error: "getStreams failed", reason: "Cannot read property 'name' of null", details: undefined, message: "Cannot read property 'name' of null…", errorType: "Meteor.Error" } app.js:1252:7
require<.imports.ui["layout.js"]</</<() app.js:1252
Meteor.bindEnvironment/<() meteor.js:1105
._maybeInvokeCallback() ddp-client.js:3557
.receiveResult() ddp-client.js:3577
._livedata_result() ddp-client.js:4736
Connection/onMessage() ddp-client.js:3385
._launchConnection/self.socket.onmessage/<() ddp-client.js:2736
_.forEach() underscore.js:149
._launchConnection/self.socket.onmessage() ddp-client.js:2735
REventTarget.prototype.dispatchEvent() ddp-client.js:175
SockJS.prototype._dispatchMessage() ddp-client.js:1160
SockJS.prototype._didMessage() ddp-client.js:1218
SockJS.websocket/ ddp-client.js:1365

The error pops up apparently in my onRendered:

So the issue arises by my own bad code, but why the difference in the browser?

This was the wrong part: call.createdBy = Meteor.user().name

import { Mongo } from 'meteor/mongo';

export const APILogs = new Mongo.Collection('apiLogs');

export function REST_Log(call){
   call.createDate = new Date()
   // call.createdBy = Meteor.user().name;