I just tried again, this time I disabled 'Option Negociation' and made it 'Bind TFTP to address' in tftpd64 and it worked! Hopefully this clears it for future reference
(I downloaded it three time before playing with the options and also changed the way I was unzipping to no avail)
Copyright (c) 1996-2015 Brocade Communications Systems, Inc. All rights reserved.
UNIT 1: compiled on Jan 26 2016 at 22:02:54 labeled as ICX64S08030f
(8496808 bytes) from Primary ICX64S08030f.bin
SW: Version 08.0.30fT311
Boot-Monitor Image size = 786944...
I am having trouble running the update_primary and update_uboot commands on my newly acquired ICX6450
(sorry if this error was troubleshooted in the past, I failed to see anyone mention this specifically)
Using egiga0 device
TFTP from server 10.0.0.192...