Can't create new projects since upgrading

This is almost certainly me being thick.

I have upgraded to Xerte X. Everything seems to work so far, except I can't create new projects. I enter a project name and click the Create button, but nothing happens.

I can duplicate existing projects, and edit and play them.

Any ideas?

Did you run upgrade.php?

<url of xerte install>/upgrade.php

Yes, I did.

No errors in the browser console? Or the server php logs?

What is your environment? The OS and webserver you use?

Console error: TypeError: document.getElementById(...).childNodes[1].filename is undefined