So, I ended up reviewing the errors in Chrome (Ctrl+Shift+I), and realized I should try what I did with Unity’s WebGL’s web.config file (I don’t have access to IIS components on the server). Which is to (web.config attached to this post) FTP up the web.config here to the same directory as the startup HTML page your project loads in the browser to show the content.
Create a file named, “web.config” in your favorite text editor. Add this code to it and save, then FTP or add next to your project’s main HTML page that loads the project.
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<system.webServer>
<staticContent>
<remove fileExtension=".gltf" />
<mimeMap fileExtension=".gltf" mimeType="application/octet-stream" />
</staticContent>
</system.webServer>
</configuration>
I hope this helps someone getting a 404 error like I was.