Google Maps - Uncaught InvalidValueError: initialise is not a function
<p>When I load the page that my Google Maps is displayed, I always see the following error in the console:</p>

<blockquote>
  <p>Uncaught InvalidValueError: initialise is not a function <em>js?sensor=false&amp;callback=initialise:94</em></p>
</blockquote>

<p>When hovering over the filename, this is showing as originating from <a href="https://maps.googleapis.com/maps/api/js?sensor=false&amp;callback=initialise" rel="noreferrer">https://maps.googleapis.com/maps/api/js?sensor=false&amp;callback=initialise</a></p>

<p>The Google Maps window and map displays absolutely fine though and has full functionality. Strangely, I couldn't find any hits on Google regarding this, they all seem to be about setLong and setLat.</p>

<p>If I change the order of loading between the API call, and the JS file, the error message changes between <code>initialise</code> and <code>google</code>. But in both cases, the map still continues to load fine.</p>

<p>Why is the error occuring, and how do I resolve it properly? Here's my google-map.js file:</p>

<pre><code>function initialise() {
    var myLatlng = new google.maps.LatLng(51.126500, 0.257595); // Add the coordinates
    var mapOptions = {
        zoom: 15, // The initial zoom level when your map loads (0-20)
        disableDefaultUI: true, // Disable the map UI
        center: myLatlng, // Centre the Map to our coordinates variable
        mapTypeId: google.maps.MapTypeId.ROADMAP, // Set the type of Map
        scrollwheel: false, // Disable Mouse Scroll zooming (Essential for responsive sites!)
    // All of the below are set to true by default, so simply remove if set to true:
    panControl:false, // Set to false to disable
    mapTypeControl:false, // Disable Map/Satellite switch
    scaleControl:false, // Set to false to hide scale
    streetViewControl:false, // Set to disable to hide street view
    overviewMapControl:false, // Set to false to remove overview control
    rotateControl:false // Set to false to disable rotate control
    }
    var map = new google.maps.Map(document.getElementById('map'), mapOptions); // Render our map within the empty div
    var image = new google.maps.MarkerImage('/wp-content/themes/bellavou/img/marker2.png', null, null, null, new google.maps.Size(70,70)); // Create a variable for our marker image.             
    var marker = new google.maps.Marker({ // Set the marker
        position: new google.maps.LatLng(51.125887, 0.258075), // Position marker to coordinates
        icon:image, //use our image as the marker
        map: map, // assign the market to our map variable
        title: 'Bella Vou at The Pantiles' // Marker ALT Text
    });
}
google.maps.event.addDomListener(window, 'load', initialise); // Execute our 'initialise' function once the page has loaded.
</code></pre>