While translating en:Tennis_scoring_system. Second paragraph of "Scoring a tiebreak game" section gives this error.
The HTML snippet to reproduce the issue:
<section id="cxTargetSection38" data-mw-cx-source="undefined"> <p id="mwmw"> <span data-segmentid="197" class="cx-segment">The server begins his or her service from the <a href="./Deuce_court" rel="mw:WikiLink" data-linkid="198" class="cx-link" id="mwnA" title="Deuce court">deuce court</a> and serves one point. </span> <span data-segmentid="201" class="cx-segment">The first of each two-point sequence starts from the server's <a href="./Advantage_court" rel="mw:WikiLink" data-linkid="202" class="cx-link" id="mwnQ" title="Advantage court">advantage court</a>. </span> </p></section>
The error is from lib/routes/v2.js
res.status( 500 ).end( error.stack );