Love the UI changes, streamlines a lot of things and you added a lot of nice features with the info organizer, however once I install the navinfocombo, It doesn't let me assign anyone to the combat group, pressing the button for it just takes me to the mansion main page.
It sounds like you are getting an error somewhere and so the game just doesn't finish the request of popping up the combat team window. I just did a fresh install of the v0.5.25 game and then dropped my navinfocombo directly into it from the zip file I uploaded and combat team button and team selection all comes up correctly and works fine for me.
Are you using any other mods?
Are there any warnings/errors in the game's secondary window?