Maya 2015x64, 4.2.
Aside from the UI issues.
You can’t save the scene after using ART. It has to do with Mental Ray Nodes that are coming in from the JointMover.mb file. If you force unload MR in 2015, you can save the scene. Somehow there are collisions with the mr nodes in 2015.
I used this workaround (renaming mr directory so it can’t be found, then removing unknown nodes) on the JointMover.mb. Works fine now in 2015.