Online Battling Error

I synced my system clock and didn't unfocus my game, but I got this error when I tried to battle online.

Exception: RuntimeError
Message: Script error within event 12, map 26 (Pokemon Center):
Exception: NoMethodError
Message: Section210:421:in `receiveInteraction'undefined method `to_pokemon' for false:FalseClass
***Full script:
pbFadeOutIn(99999) {
OnlineLobby.open
}

Interpreter:243:in `pbExecuteScript'
** Online Lobby:408:in `each'
** Online Lobby:408:in `receiveInteraction'
** Online Lobby:144:in `start'
** Online Lobby:132:in `loop'
** Online Lobby:222:in `start'
** Online Lobby:38:in `main'
** Online Lobby:20:in `open'
(eval):2:in `pbExecuteScript'
(eval):1:in `pbFadeOutIn'

Interpreter:276:in `pbExecuteScript'
Interpreter:1600:in `command_355'
Interpreter:494:in `execute_command'
Interpreter:193:in `update'
Interpreter:106:in `loop'
Interpreter:198:in `update'
* Scene_Map:103:in `update'
* Scene_Map:101:in `loop'
* Scene_Map:139:in `update'
* Scene_Map:68:in `main'

My game just froze when I challenged you I couldn't do anything more...

That error means that your opponents team wasn't sent to the server in time for the connection to occur. Are you sure your friend time was synced, window wasn't unfocused? (everything was ok on your side)

He said he was synced. Don't know if he unfocused his window though. I was battling Wubba (post above).

Yes when I challenged him, I kept focusing the game, but then my screen just froze for whatever reason... And when he tried it I don't quite know... Maybe it's my fault?