This could be due to the 16 bit simulator being turned on. Go to Start -> Programs -> Concept... -> then select 'Simulator 16-Bit'. If it says 'Concept-SIM is ON' simply turn it off. If it says 'Concept-SIM is OFF', toggle it ON then OFF before closing the window and trying the upload again.
Legacy KB System (APS) Data: RESL212866 V1.0, Originally authored by DaSo on 10/24/2013, Last Edited by DaSo on 10/24/2013
Related ranges: Concept