Can't create articles here

Installation info

Modx: Revolution 2.3.1-pl (traditional)
Articles: 1.7.9-pl
Quip: 2.3.3-pl

Articles seems to be installed in package management.
When I right click a document in the tree menu and click 'Create Articles here', the browser redirects to:
http://www.mydomain.com/manager/?id=166&a=resource/create&class_key=ArticlesContainer&parent=166&context_key=web

However, the right pane of the manager remains blank. If I click the resource again, the page is still a regular document instead of a new articles container.

The error logs shows absolutely nothing.

My question is twofold:

1: How are you supposed to debug a situation like this?
2: What could be causing this?

I'm having the same issue on 2.33 and latest articles. Never had this before but difference might be that this in an old site that I'm adding Articles to whereas everything else is from scratch?

Did you ever get anywhere with it?

Thanks

Phil