Bug When I am moving around after every 2 min my abilties do not work

So I have a bug where when I am playing it does not allow me to use abilities and just gives an explination point every time I click and or does not allow me to do anything unless I ult tab. It's not a FPS issue as I have 200 + fps its a bug issue unless maybe you can cell me what I might be licking to cause this on the keyboard.