OpenSeaDragon not displaying multiple images in dzc_output.xml file

I'm trying to display multiple images with OpenSeaDragon. I used Deep Zoom Composer to create the image files and it produced the following XML file (abridged):

dzc_output.xml:

<?xml version="1.0" encoding="utf-8"?>
<Collection MaxLevel="8" TileSize="256" Format="jpg" NextItemId="5" ServerFormat="Default" xmlns="http://schemas.microsoft.com/deepzoom/2009">
  <Items>
    <I Id="0" N="0" Source="dzc_output_images/ft1.xml">
      <Size Width="825" Height="584" />
      <Viewport Width="5.2402050398801272" X="-0" Y="-0" />
    </I>
    <I Id="1" N="1" Source="dzc_output_images/ft2.xml">
      <Size Width="824" Height="583" />
      <Viewport Width="5.2375806686733934" X="-1.0500455705877254" Y="-0" />
    </I>
    <!--3 more images not shown as not necessary-->
  </Items>
</Collection>

I created a very simple HTML page to display the viewer (I plan to use Django for the final project). I created the viewer with the following code:

var viewer = OpenSeadragon({
                id: "openseadragon1",
                prefixUrl: "openseadragon/images/",
                tileSources: "imagesources/dzc_output.xml",
                sequenceMode: true
            });

I'm using python -m http.server to serve the folder that the html page is in. It worked fine for single images. However, with this dzc_output.xml file containing multiple images, the viewer displays "Unable to open [object Object]: Unable to load TileSource" when I load the page. Scrolling through the images produces this error: "Unable to open [object Object]: HTTP 404 attempting to load TileSource"

I'm not sure what the problem is here. Any help would be good.