Complex accept header throws "Error translating between RDF formats"

[rubensworks]

When requesting a simple document such as

<ex:s> <ex:p> <ex:o>.

with the complex accept header application/n-quads,application/trig;q=0.95,application/ld+json;q=0.9,application/n-triples;q=0.8,text/turtle;q=0.6,application/rdf+xml;q=0.5,application/json;q=0.45,text/n3;q=0.35,application/xml;q=0.3,image/svg+xml;q=0.3,text/xml;q=0.3,text/html;q=0.2,application/xhtml+xml;q=0.18 throws the following error:

Error translating between RDF formats