I was running a custom game (metronome) tournament in the Sun & Moon room earlier and had to dq one participant for not using one of the pre-approved teams and got the following error message -
"Unexpected InvalidMatch from setMatchResult([yukixenon, sukhjit], win, 5,6) in onBattleWin(battle-gen7customgame-652761672, yukixenon). Please report this to an admin." - reporting it as requested.
I don't know if this has anything to do with it, but there were some funky things with the rules for the tournament - I used the /tour banlist command to unban specific mons/moves (/tour banlist !giratina, !lugia, !zygarde, !regigigas, !cresselia, !type:null, !metronome, !recycle), which apparently doesn't work, but maybe it messed with something.