We have recently discovered a compatibility issue between the latest Mac OS X Update (El Capitan 10.11.4) and ETC Gadget and ETCnomad programming wings. These devices are not correctly detected and are unable to output DMX as a result. ETC is actively investigating the issue with Apple and hopes to have a resolution soon. In the meantime, ETC does not recommend updating to OSX 10.11.4 until this issue is resolved. (We have confirmed that this is new to 10.11.4 - version 10.11.3 does not exhibit the same behavior).
A firmware update is required to fix this issue. Instructions and the firmware can be found here:
http://www.etcconnect.com/Products/Consoles/Eos-Family/ETCnomad-ETCnomad-Puck/Software.aspx