WebGL app only displays blank, white rectangle.

Questions & Answers
1

I’ve built my app for WebGL.
The app will run perfectly fine and as expected, locally with Firefox.
However when I uploaded to my webspace it will run with neither Firefox or Chrome.
I initially had the ‘Incorrect Header’ issue but I resolved that by adding a web.config file to the ‘Release’ folder in the uploaded build.
I got the web.config file from this thread:

https://forum.unity3d.com/threads/webgl-incorrect-header-check-bug-again-in-latest-beta.411725/

and the code for the file is thus:

        <?xml version="1.0" encoding="UTF-8"?>
        <configuration>
            <system.webServer>
                <staticContent>
                    <mimeMap fileExtension=".mem" mimeType="application/octet-stream" />
                    <mimeMap fileExtension=".data" mimeType="application/octet-stream" />
                    <mimeMap fileExtension=".unity3d" mimeType="application/octet-stream" />
                    <mimeMap fileExtension=".memgz" mimeType="application/octet-stream" />
                    <mimeMap fileExtension=".datagz" mimeType="application/octet-stream" />
                    <mimeMap fileExtension=".unity3dgz" mimeType="application/octet-stream" />
                    <mimeMap fileExtension=".jsgz" mimeType="application/octet-stream" />
                </staticContent>
            </system.webServer>
        </configuration>

As I say, this stopped the Incorrect Header issue and now the Unity frame displays with the white rectangle on the white background with the Unity logo in the bottom left and the name of my app in the bottom right.
That’s as far as it goes, though. It stops there.
I pulled up the Browser console when I ran it and it gave me this error.

88880-error.jpg
88880-error.jpg997×607 86.5 KB

I’m afraid my technical knowhow is limited to a very basic knowledge of Javascript and HTML. I wasn’t expecting to have to dig in to server programming too. I’d imagine the error is probably glaringly obvious but I’m afraid it’s gibberish to me.
If anyone can help, I’d be extremely grateful.

Thanks

Wayne

2

I’ve done a little research and tried a few things but sadly to no avail.

I have tried removing the .htaccess file. This, of course no longer exists, so there was nothing to remove.

Increasing the memory size to 512 from 256. This made no difference.

Making a development build. Made no difference.

Making a build with compression off. Made no difference

I looked for the Mime settings in my server control panel (on my web host’s site) but despite an array of options, there was nothing mime related.

I wish I at least understood what was causing the internal server error. I could at least focus my investigation on that.
Something about the Unityloader.js script seems to be giving the browser grief but I’ve no idea what.