New player, sorry if this has been answered before: when I'm playing, often in the middle of a battle, all the icons go gray and I cannot do anything. It's not cooldown timers, I see those all the time, but this is for all my skills. Happens multiple times per hour, I'd say 80% of my deaths are due to this. Here's what it looks like:

https://www.dropbox.com/s/qqxssmmugqwcg0b/Gray.jpg?dl=0

Any ideas what I might be doing wrong?

Thanks for any help.