I was browsing and all of a sudden some epic appeared and when I pressed the attack button it just turned gray and did nothing.
( I couldn’t even get a photo
Sad 
ikr that s sad
I was so mad when t just wouldn’t work I had to leave the battle
Maybe you have to let the opponent attack after the button turns gray.
It wasn’t attacking and my attack didn’t do any dmg and it wasn’t on a rampage