Plone 4.3 has disabled plone_deprecated CMF layer by default (see https://github.com/plone/Products.CMFPlone/commit/90d9ab4e1957fa206cf5ea2d602d691d2ac22c58). This broke the default Collage view as it was using here/document_relateditems/macro/relatedItems. This would probably break pre-Plone4 setups where the relatedItems viewlet is not in place, maybe it's worth no note it in the documentation.
Merge pull request #2 from sneridagh/master

Main Collage view broken for Plone 4.3.

Looks good to me