"Everytime I try to trade with one specific person, it locks up the whole game."

#PokemonGO: Very weird situation. At a friend's house, and I can successfully traded with everyone except for one person. He is also able to successfully traded with everyone else.When we go into the trade menu, nothing happens until eventually the game gives us both an "Unknown Trade Error". After that, the game completely fails to to load any data from the servers. Can't load our medals, can't load our friends list, can't load defenders, and when we try to restart the game it doesn't load either. After about 5 minutes, we are finally able to get back in the game and the process repeats if we try to trade again.Anybody ever had this happen, or have any idea what to do? Any advice would be much appreciated.Update: Even tried different devices, so this seems to be an account issue. Here's another thread about the same thing.http://bit.ly/2UXYLWM via /r/TheSilphRoad http://bit.ly/2KEGY2N