HTML pages not loading after export

At the risk of looking foolish, am I missing something?

After exporting a title to XML, I can't seem to get the pages to load in a browser - I just get stuck at the 'SPP Top Page', with just the background colour loaded. Media files in the directory can be loaded correctly in the browser. Even after importing working titles and re-exporting them, I still have no luck. Tested on multiple browsers and several computers

In Chrome I get two errors in the console - Uncaught DOMExceptions in the trivantis-pagePlayer.js and trivantis.js files.

In Edge the elements are all locatable using the Inspector but cannot be seen or interacted with

In IE, if Responsive Pages was enabled in the title, some elements appear when the Console/Inspector is open (because scaling), but they have no interaction.

Have I missed something really obvious in setting up the title or when publishing? A very basic example is attached

Thanks in advance