That's a strange bug, and I'm not able to replicate it myself and it doesn't appear to be coming from the base mod. Do you have any extra "addons" you might try turning on or off? I notice you have the radar icons script, could you try temporarily disabling it (like renaming the extension) and see if that fixes it?
I was afraid it might be one of the mods. Hopefully it's not radar icons, but I'll give it a try. If it is, I need to figure out a way to make Trimurti "ignore" the mods, since they're applied within the MVPs and moving those files in and out specifically to play Trimurti would be inconvenient. :x
EDIT: Alas, it was the mods. Full disclosure, I actually had a buddy running through the campaign on the exact same install setup as me to ensure everything worked without a hitch so I could avoid spoiling what would otherwise be a blind playthrough next week. So there's been some delay in troubleshooting as I act as the middleman. He said that the issue only occurs specifically when he tries to Commit to the 9th mission. Is there something specific in that mission (no spoilers please!) which
either the message box mod or
radar icons mod would cause?
We don't know which one it was, since he just removed the entire data folder from both FSPort MVPs 4.3.5 and MVPs 4.3.3 which Trimurti uses.
EDIT2: My pal also wanted me to tell you that your campaign is, and I quote "really feckin' awesome".
EDIT3: I'll see if we can't narrow down which mod it is, and I'll get back to you. Yup, it's the radar icons mod.