Make sure that the the correct path to the firmware files is shown in the Folder.
Select Copy New Files From Elecraft Server into Local Folder and then click Check Versions Now to get firmware files from Elecraft.
The required files are:
The following additional file is required to load firmware into the DSP2 of the optional KRX3 second receiver:
A DSP2 firmware code file, "hauxNNNN.hex", where "NNNN" is the revision number. This file may not be available on the Elecraft file server until the KRX3 second receiver option is available.
The following additional file is required to send firmware to the optional KDVR3 Digital Voice Recorder:
A DVR firmware code file, "hdvrNNNN.hex", where "NNNN" is the revision number. This file will be published on the Elecraft file server when the KDVR3 Digital Voice Recorder Option is available.
"hfwnotes.rtf" is required for the K3 Firmware Release Notes Help menu item.
The "K3UtilityVersionInfo.txt" file is used to detect that the K3 Utility is no longer current.