Footseitch3.0 not installing

Footswitch 3.0 update not installing.
Follow steps on screen
Unplug footswitch control chain (goes dark)
Hold switch 1 and plug in FW usb to Mod Duo
(Remains dark)
Wait 30 seconds then unplug usb. Plug in control chain.
(FW screens light up & show previous upgrade)
(Power down/up Mod duo & no differance)
What am I missing?