ZAT and ZCLI theme previews not working on Article page

Over the last few days both the ZAT and ZCLI local theme previews are not working on the Article page. 

It happens using both tools, and regardless of the theme that's used. Only the Article page is affected. An error is displayed, which is at the platform level (not the theme's Error page):

I was directed here by the Zendesk Support team even though this appears to be an issue with either the platform or account. Is there anyone able to help troubleshoot this from the Zendesk side (perhaps using the request ID above)? This is preventing us from getting work done and is urgent.