After hunting and defeating an enemy creature with my lv 2 cat (7 hunter stage) in a colosseum game, I was asked to select an effect to execute first (probably intended to be chosen from the evolve and the jazz dog effect, even though the latter didn‘t matter as the creature was already defeated). However, the menu was empty and there was nothing to click (see screenshot).
After reconnecting, the game was still prompting me to select an effect, but clicking the prompt (other screenshot) did nothing. This caused me to immediately lose the game.