I'm trying to setup CX on my wiki. I've installed CX and VE following the instructions on mw.org, and Special:ContentTranslation loads fine. However, if I try to translate a page containing references (e.g. https://en.wikipedia.org/wiki/User:Testpitanormal/toPt), I get a blank page with a console error:

inheritClass: Origin is not a function (actually undefined)

I realized that this happens because VE has:

OO.inheritClass( ve.dm.CXReferenceNode, ve.dm.MWReferenceNode );

but the latter only exists if Cite is installed.

Based on mw.org, Cite is an optional dependency, so this should fallback more gracefully.