VKB-SIM

I currently own a Modern Combat Mk III PRO with twist.

It's attached to a backbox. I noticed there was a firmware update. Can you tell me which firmware I need to flash? There are so many blackbox ones, and a couple of MCG pro ones, which one do I flash?

If you have a MKIII GunFighter base most probably you have a black Black Box - in this case you should flash this file: _BlackBox_MK2_GF_MCG_PRO_Twist_vx_xx_x.vkb (make sure there's 'MK2' in file's name and 'Twist'. Here's the whole process.

Thanks I couldn't figure out if I should do MK II, since I have an MKIII. I appreciate the help.

The "MKII" in the firmware refers to the Black Box (black version is MKII) and not to the version of the base (which in your case is MKIII).
No labeled firmware for GF bases is for the first iteration of the Black Box (the orange one).

Everytime I go to flash it, this is what happens:

https://imgur.com/4rrUJwh

Try to download the firmware again. And please do follow the guide that I've posted above. Also, be signed in as Admin on your computer and run the whole process as Admin.