[android] Unable to add window -- token null is not valid; is your activity running?

PopupWindow can only be attached to an Activity. In your case you are trying to add PopupWindow to service which is not right.

To solve this problem you can use a blank and transparent Activity. On click of floating icon, launch the Activity and on onCreate of Activity show the PopupWindow.

On dismiss of PopupWindow, you can finish the transparent Activity. Hope this helps you.