I was clicking hide, hide, hide for the stories near the bottom of the front-page until I got this back:
https://news.ycombinator.com/snip-story?onop=news&id=1206078...

[" <tr class='athing' id='12065699'>\n <td align=\"right\" valign=\"top\" class=\"title\"><span class=\"rank\">1.</span></td> <td valign=\"top\" class=\"votelinks\"><center><a id='up_12065699' onclick='return vote(this, \"up\")' href='vote?id=12065699&amp;how=up&amp;auth=099c6eb692711a8f986d31bf0f7d86021ded1115&amp;goto=snip-story%3Fonop%3Dnews%26id%3D12060787'><div class='votearrow' title='upvote'></div></a></center></td><td class=\"title\"><a href=\"https://coding.net/u/jinzw/p/mathEditor/git\" class=\"storylink\">A WYSIWYG math editor</a><span class=\"sitebit comhead\"> (<a href=\"from?site=coding.net\"><span class=\"sitestr\">coding.net</span></a>)</span></td></tr><tr><td colspan=\"2\"></td><td class=\"subtext\">\n <span class=\"score\" id=\"score_12065699\">63 points</span> by <a href=\"user?id=tvvocold\" class=\"hnuser\">tvvocold</a> <span class=\"age\"><a href=\"item?id=12065699\">1 day ago</a></span> <span id=\"unv_12065699\"></span> | <a href=\"flag?id=12065699&amp;auth=099c6eb692711a8f986d31bf0f7d86021ded1115&amp;goto=snip-story%3Fonop%3Dnews%26id%3D12060787\">flag</a> | <a href=\"hide?id=12065699&amp;goto=snip-story%3Fonop%3Dnews%26id%3D12060787\" onclick=\"return hidestory(12065699)\">hide</a> | <a href=\"item?id=12065699\">21 comments</a> </td></tr>\n ",null]

What happened? (refreshing the page makes it work again)

Edit: there it is again:
https://news.ycombinator.com/snip-story?onop=news&id=1207486...

Steps to reproduce:
https://news.ycombinator.com/hide?id=12074096&goto=news
https://news.ycombinator.com/hide?id=12073011&goto=news
https://news.ycombinator.com/hide?id=12074388&goto=news
https://news.ycombinator.com/hide?id=12074388&goto=news (last news item on front-page)

https://news.ycombinator.com/snip-story?onop=news&id=1207438...

[" <tr class='athing' id='12065592'>\n <td align=\"right\" valign=\"top\" class=\"title\"><span class=\"rank\">1.</span></td> <td valign=\"top\" class=\"votelinks\"><center><a id='up_12065592' onclick='return vote(this, \"up\")' href='vote?id=12065592&amp;how=up&amp;auth=7b542c4f6ee7726621bada191c3874162d4475d1&amp;goto=snip-story%3Fonop%3Dnews%26id%3D12074388'><div class='votearrow' title='upvote'></div></a></center></td><td class=\"title\"><a href=\"https://www.bloomberg.com/view/articles/2016-07-04/brexit-is-a-lehman-moment-for-european-banks\" class=\"storylink\">Brexit Is a Lehman Moment for European Banks</a><span class=\"sitebit comhead\"> (<a href=\"from?site=bloomberg.com\"><span class=\"sitestr\">bloomberg.com</span></a>)</span></td></tr><tr><td colspan=\"2\"></td><td class=\"subtext\">\n <span class=\"score\" id=\"score_12065592\">200 points</span> by <a href=\"user?id=vool\" class=\"hnuser\">vool</a> <span class=\"age\"><a href=\"item?id=12065592\">1 day ago</a></span> <span id=\"unv_12065592\"></span> | <a href=\"flag?id=12065592&amp;auth=7b542c4f6ee7726621bada191c3874162d4475d1&amp;goto=snip-story%3Fonop%3Dnews%26id%3D12074388\">flag</a> | <a href=\"hide?id=12065592&amp;goto=snip-story%3Fonop%3Dnews%26id%3D12074388\" onclick=\"return hidestory(12065592)\">hide</a> | <a href=\"item?id=12065592\">146 comments</a> </td></tr>\n ",null]