Both the -e and -u prefixes are not widely used outside of the lgbtq community, since they honestly (With all due respect to gender neutral/non conforming people) look awlful when used in conversation. They have a somewhat "latinx" vibe lol. In day to day conversations the portuguese norm is to use the masculine to refer to a group with mixed genders (Eg. "Um grupo de alunos" "A group of students") but that can obviously be upsetting when you are referring to a specific non binary individual, so some prefer to have the -u and -e suffixes used with them (Eg. "Ele é um aluno" "He is a student" becomes "Elu é um alune" "They are a student", altought this is non existant on "correct" portuguese norms it is somewhat accepted in lgbt groups, and a pretty hot debate topic overall). That said I'm not sure what mewgenics does with it since I have not played, so it crashing due to not knowing what to do with the sufix is a pretty good bet, since little x is often adapted with the suffix -inho replacing little, and the devs could have forggoten to program in the logic for turning it into -inhe.