A couple of hours ago I was reading an answer on EL&U, which was posted four months ago, when I noticed two Google Books Ngrams were completely empty. The two graphs are completely blank except for the X and Y axis and a small yellow square positioned at the top centre.
I posted a comment pointing out the anomaly and the answerer confirmed that the graphs were devoid of detail, although by replacing the word "chart" with "graph" in the URL, everything returned to normal. They also added that a similar graph posted on a different answer appeared to be unaffected, and in fact the word "chart" is embedded in the link.
I searched in the archives for other instances but could not find any. Is there a fix for this bug?
In light of the lightning downvote, I want to add that there's nothing to suggest that this weird anomaly is restricted to EL&U.