It should all be latest, I just installed Launchbox a couple of days ago. It's a fresh install of Windows on a brand new PC.
I misspoke when I said Dolphin worked outside of Launchbox, I realize I only ever tested the Dolphin core for RetroArch. After tracking down the Dolphin install that I downloaded through Launchbox, I am unable to open it, so I assume this isn't a Launchbox issue. Not sure why I can't launch the RetroArch core through Launchbox either though... possibly related?
Launchbox is correctly pointing to the rom files and correctly set to Dolphin. I assume its a non issue since my other roms work fine but maybe its worth mentioning just in case- all of my roms are on a samba network share. I did try your suggestion of changing the command-line params, as well as unchecking "attempt to hide console window" but still no dice
I'm going to try manually installing Dolphin and replacing the version in Launchbox > Emulators, and if that doesn't work then I'll head over to the Dolphin folks to see if they can help me out, maybe my odd hardware is causing an issue. I might also try reinstalling Launchbox.
I appreciate the replies, I'll be back if I can figure it out.