[translations] Error in generate-documentation.log

[Walter Garcia-Fontes <walter.garcia@xxxxxxx>]

I've been working on fixing unstralated node references in the
learning directory of the Catalan translation. I believe I fixed all
of them, but now the build is aborting with an error message in
generate-documentation.log:

fatal error: define-grob-properties.scm: cannot find interface for property:
voiced-position

Anybody can give me a hint on where I have to look for the culprit of
this? 

Thanks a lot,

-- 
Walter Garcia-Fontes