[mac] cannot copy-paste text on in-game chat

i play on mac computer and i cannot copy-paste text (like a flash cooldown) on in-game chat. cmd-a, cmd-c and cmd-v: none of these works on in-game chat. if i copy some text out of game (cmd-c), then go in game and try to paste it (cmd-v), the letter "v" will simply appear in chat.