[Elecraft] KAT Utility input using MAC

[stephen arnold]

A little help, please.  

I am using a MacBook Pro for shack computer.  I am getting the K3 and KPA 500 firmware updates with no problem using this computer. 

However,  the KAT 500 tuner will not recognize the MAC for the initial utility download.  I am using the SerialPort 2 for K3 firmware which does not appear when I have attempted to upload the utility program into the tuner.  When I attempt to refresh Port List, the Serial port choices do not appear, and the computer and KAT 500 turner (a kit) do not recognize each other.

What have I missed, or, have I committed an error in the kit construction. 

Thanks,   Steve KB9AVS