ArcGIS Api (Esri) triggering multipleDefine error - dojo

Question

I have this weird issue while using ArcGIS API for JavaScript v4.4 in my code. I am trying to build an Excel Web Add-in in which I would like to load an ArcGIS map but when I load ArcGIS I get a multipleDefine error.
ArcGIS is getting bundled with Dojo which is used as the loader for all the ArcGIS/esri packages. I have no other choices to load my own custom JS bundles with Dojo because of the way ArcGIS has built their API. So I can't decide to not use Dojo and thus not getting the multipleDefine error.
I load my own JS files like this:
<script src="https://appsforoffice.microsoft.com/lib/1/hosted/office.js" type="text/javascript"></script>
<script>
var dojoConfig = {
parseOnLoad: false,
async: false,
// we make aliases for our js file
aliases:  [
['index',  './Bundles/index.js'],
],
};
</script>
<script src="https://js.arcgis.com/4.4/init.js"></script>
<script>
require(['index'], function (index) {
//...do something
});
</script>
When I restart the page I get a multipleDefine error once in every two/three trials. After a lot of investigation I understood that the error lies with the Office.js API but I had a hard time to find a good solution.

Answer 1

After a while I found the cause of the problem; we cannot start office-js and Dojo together because they both want to add scripts in the head tag of our page and somehow they end up in conflict with one another, thus we get the dreaded multipleDefined Dojo error and some of our files do not get loaded.
Once this cause was identified I decided to solve it by making sure Dojo, Argis and my custom js files got loaded once Office and dependencies were fully loaded.
I implemented it like this in my js code:
// This Dojo config variable has to be defined before Dojo is loaded in our scripts
var dojoConfig = {
// we make aliases for our custom js file
aliases: [
['index', './Bundles/index.js'],
],
// We require our dependencies (our own code bundles) with Dojo.
// Notice that it is mandatory to bundle our js files
// as AMD Modules for Dojo to be able to load them as dependencies.
deps: ['index'],
};
// Once office has fully initialized we can add our arcgis file and let
// him load our own required javascript files.
// We cannot start Office-js and Dojo/Arcgis together because they both
// want to add scripts in the head tag of the HTML page and
// somehow they end up in conflict, thus we get the dreaded
// multipleDefined Dojo error and some of our files
// do not get loaded.
Office.initialize = function (reason) {
// we manually add the Arcgis script to the header of our page
// once we are sure Office and dependencies has fully loaded.
var tag = document.createElement('script');
tag.src = 'https://js.arcgis.com/4.4/init.js';
document.getElementsByTagName('head')[0].appendChild(tag);
};
Once this was added the code started working like a charm.