Xfce 4.12 was released in February 2015 while finally getting ready to succeed that is the long talked about Xfce 4.14 that is expected to ship this month.
With Xfce 4.14, most of the Xfce components should now be in good shape following a lengthy GTK3 porting process from GTK2. Xfce 4.14 should be playing much better with the other latest upstream software components, improvements for display/multi-monitor setups, and a plethora of bugs got fixed along the way.
Xfce 4.14.0 should be out in “mid-August” while Xfce 4.14pre3 was released this week as the anticipated final snapshot for testing.
Xfce 4.14pre3 has some race condition fixes, a number of compositing fixes within xfmw4, a fix for mounting external drives within the Thunar file manager, and many other fixes throughout.
More details on Xfce 4.14pre3 and its fixes can be found via this blog post.