I am having an issue with getting any of the USB attacks to work on the Nexus 9. I have tried with and without USB debugging, with and without MTP enabled with no joy. I have tried it on 3 computers with the same results.
Android Version
5.0.1
Kernel Version
3.10.40-g6f3881e-dirty
root@kali #1
Sat Mar 28 00:22:24 EDT 2015