That window may come from a client on a different machine, or from a client on this machine but which is connecting to the X server via TCP. Why don't you xkill it?

You may also want to try its parent windows run

xwininfo -children -id 0x04c00004

to figure it out.

That window may come from a client on a different machine, or from a client on this machine but which is connecting to the X server via TCP. Why don't you xkill it?

You may also want to try its parent windows run

xwininfo -children -id 0x04c00004

to figure it out. And then you can check if the parent window has a pid.

ps -fp "$(
  xprop -id "$(
    xwininfo -children -id 0x04c00004 |
      sed -n 's/.*Parent window id: \([^ ]*\).*/\1/p'
  )" _NET_WM_PID | sed 's/.* //'
)"

That window may come from a client on a different machine, or from a client on this machine but which is connecting to the X server via TCP. Why don't you xkill it?

You may also want to try its parent windows run

xwininfo -root -tree

to figure it out.

That window may come from a client on a different machine, or from a client on this machine but which is connecting to the X server via TCP. Why don't you xkill it?

You may also want to try its parent windows run

xwininfo -children -id 0x04c00004

to figure it out.