Keybind issue

[man9k]

So I've got this:

X Error of failed request:  BadAccess (attempt to access private resource denied)
  Major opcode of failed request:  33 (X_GrabKey)
  Serial number of failed request:  10
  Current serial number in output stream:  11

I can't figure out what else is using this bind, also tried to bind on other keycode but it did the same result.
Ubuntu 15.10
@maaatts need your help I guess

[maaatts]

I installed Ubuntu 15.10 to try and I am unable to reproduce the problem. Are you using Unity, or another DE/WM?

[man9k]

unity 7.3.2, I removed bind section and hack works. As google said, something is using this combination, but how to figure out what is that something?! Kill processes to determine the gilty?