I did a search for "pina colada", and the first result should have been this:
https://en.wikipedia.org/wiki/Pi%C3%B1a_colada
Notice the way the URL is supposed to be encoded. Instead, the first result was this:
https://en.wikipedia.org/wiki/Pi%EF%BF%BDFDFDa_colada
which contains an invalid UTF-8 sequence.
This URL should have appeared instead:
https://en.wikipedia.org/wiki/Pi%C3%B1a_colada