My Wacom pen is not working properly with Fedora 23 and Gnome 3.18. Every time the touchscreen and pen are used simultaneously, the system will freeze for 3-5 seconds. It seems an issue of Gnome, because if you downgrade Gnome to any version before 3.16, the problem disappears.
Denis Auroux offered a decent solution to this problem. Here comes the way to use it.