MC75A HF (RFID) - Cannot run HF RFID demo app

Device - MC75A6-P3CSWRRHF3R
S#: 11112522503253
TERM:WLP,BB,HF,256/1GB,NUM,WM6.5-FR,15X*
Originally loaded with French OS 
SNCF sticker on back of device

Upon receipt of unit (originally French), I was able to successfuly load a CAB file ("MC75ARFID.CAB", which came from "75A6w65HenPS810100.zip") which creates a sample app ("MC75RFID.exe").  I would then run "MC75RFID.exe" on device without error.

However, I decided to flash the device with an English version of OS (see file names below*) and install CAB file again (copy "MC75ARFID.CAB" to device, double tap CAB file on device).  The cab file successfully installed, however, when I go to run the "MC75RFID.exe" app, I get an error.

Error says: "The file 'MC75RFID' cannot be opened.  Either it is not signed with a trusted certificate, or one of its components cannot be found.  If the problem persists, try reinstalling or restoring this file.

OSUpdate file names I tried loading...
* "75A6w65HenU1023701.zip" and "75A6w65HenU2023701.zip"
* "75A6w65HenUL023701.zip"

I also tried reloading the French OS ("75A6w65HfrUL023701.zip") and I still get same error.

Can anyone point out what I may be doing wrong?  I need to get the sample application up and running.