When placing the robber and accidentally selecting a player with 0 resources, don't penalize
One thought, and it may have been mentioned before, but when you place a robber on a position that has multiple players, you shouldn't be penalized with getting 0 resources if you carelessly selected the player with 0 resources because you forgot to check their resource count. If it was a real life game, the player would say "I have no resources" and you would take from a player on the spot you robbed that has resources. If you accidentally select the player with 0 resources, there should be a prompt notifying you they don't have resources, which you then can close and subsequently take from someone who does.
admin edit: done. will go live in v98