At https://en.wikipedia.org/w/index.php?title=Type-1_OWA_operators&oldid=712327239
there are a number of "Failed to parse (Conversion errors)". Tracing this down it seem to be a problem with
\mathop \vee \limits_a^b
This syntax seems to work in MathJax. Things work fine if \mathop is replaced by \operatorname
\operatorname{\vee} \limits_a^b
In standalone latex you get different results using \mathop and \operatorname.
I've fixed the page in question.
It also occurred and was fixed at