Again it's a one man hobby project, I don't have a team of people to go through every formulation and every error message to ensure nobody can read them in a way that offends them. It's just me, writing code on an unfinished project that HN discovered.

In this case, the code doesn't match the word regexp, like it may be a @TwitterHandle or a "comp.lang.c" with periods in it, or an unsupported Unicode range. It doesn't know why it is not matching, just that it doesn't.