So if he is sharing his map with you and you can't see it, leave the game then come back into it. If that doesn't work, leave the game, clear your cache, and then enter the game again. If he is sharing Right of Way with you, then you shouldn't be able to see his map. You can skip to Sharing Maps without even thinking about going to Right of Way
I have problems going into a game that I have played for about a week. It only shows the loading screen with no words. When I cleared my cache, it then showed me the loading screen again, but this time it has words on it.