neoman782
Fisherman
As a little test, I moved the friendship value of one of my pokemon to the maximum number. I then leveled that Pokemon up. The game closed when I leveled him up. Unfortunately, it did not give me a crash report. I then lowered the friendship below the max and then tried to level him up again. That time it worked. I can only conclude that once a Pokemon has maxed out its friendship value, leveling it up or increasing its friendship must cause the game to close.