Cisco’s new Catalyst 3850 offeres an array of features including 480 Gbps stacking bandwidth, 802.11ac wireless, built-in wireless controller with 40 Gbps wireless throughput and IOS XE.
With IOS XE code release 03.02.01.SE there is a major defect:
7.42 EMP: APs fail to join after staggered boot of 4M stack
This causes any associated access points to the built-in mobility controller to loose attachment to the 3850 mobility manager. At current, Cisco is working to repair this bug on the next IOS XE release, for now the only repair is a switch stack power cycle.
A similar bug exists with the same release code where inserting a SFP+ module requires a switching power cycle to use<Bug CSCud68775>.