After adding a couple of URL relationships, it gave this error and it's impossible to view that artist page.
The host and the stack trace keeps changing, but the exception caught is always the same.

Internal Server Error
Oops, something went wrong!

Error:

Caught exception in MusicBrainz::Server::Controller::Artist->show "Can't use string ("") as an ARRAY ref while "strict refs" in use at lib/MusicBrainz/Server/Data/WikipediaExtract.pm line 33, line 3."
Stack trace:
line 33 MusicBrainz::Server::Data::WikipediaExtract
line 49 MusicBrainz::Server::Controller::Role::WikipediaExtract
line 9 MusicBrainz::Server::Controller::Role::WikipediaExtract
line 332 MusicBrainz::Server
line 306 MusicBrainz::Server
line 333 MusicBrainz::Server
line 347 MusicBrainz::Server
line 392 MusicBrainz::Server
Request data:

$VAR1 = {
'query_parameters' => {},
'body_parameters' => {}
};

Host: asterix

URL: http://musicbrainz.org/artist/d6f92a09-2d52-4d28-a474-38204c08e3ad