whenever i select my hero and put it on heroes hall (theres sword icon on the top right side of the hero).. then i go fight ( for example Resources raid or on arena) he's not there.. i have 4 heroes hall and 5 heroes, but i can only use 3 of them... why is this happening?
i already have town hall lvl 5.. before the update i can use 4 of them, 

Each different battle type has it's own team.  You prob have to set that team.
Click your guild hall, and chose the attack formation button.
You can also click on each event and edit formation there too.

Help! Whenever I go arena, it only allows 4 heroes to participate. I am at town hall 7 and I have 5 hero Halls filled with heroes. I tried to go to attack formation, I am only allowed to bring 5 heroes for resource raids. It always tells me that I left a hero hall empty  whenever I play arena.