The ProWORX Nxt EXECLoader Wizard is the same EXECLoader Wizard that Concept uses and it does not support the PC-E984-X8X PLC. The only way to flash the is to do the following;
1. Open ProWORX Nxt
2. Go to the controller tab and select EXECUTIVE FLASH
3. You will then select Write, and then browse to where the source of the exec firmware is and the destination address of the target PLC.
You will now be able to flash the PLC.
Note: The Compact product line and Prowox software is obsolete and has been replaced with the M340 product line.