I recently purchased a FortiGate 60D 3G4G VZW firewall and want to update to the latest firmware version. However, each firmware image I have downloaded fails to install, saying it is the wrong image type. I've tried a number of the 5.0 and 5.2 images for the "FGT_60D-v5-buildXXXX" trains. Each fails to install, despite being listed as a supported model in the release notes. This happens from the CLI or GUI, local upload or from Fortiguard services.
Can anyone point me in the right direction to where I can get my hands on the correct firmware for this device?