VKB-SIM

I updated my Gladiator NXT from v2.08.0 to v2.16.5 which seamed to go fine. However a red light is now blinking between the F2 and F1 button.
I've opened it up and everything looks good and it appears to be working fine, although using the VKBDevCfg-C tool returns an "access violation error.

Any idea what this could be? is there away to retune to the older firmware?
Thanks

What version of VKBDevCfg-C do you use?
You can update firmware directly using zbootloader.exe. Launch this tool, double click your VKBsim Gladiator NXT in the list. You will see Boot device detected - OK. Select fw file and press Flash It!
PS.
Tried 2.165 for mine - no issues( After all (suggest - success) please show External - LEDs tab screenshot.