been observing something that seems to be a bug in recent version 4.1.? (Epic Games->GalaCiv III )
near the end of my recent game (excessive galaxy) i had the situation that i created 3 citizens at once, transformed them into diplomats and sent them across the galaxy to a planet to gain enough influence there to get the influence win.
i ended my turn, got "lost citizen", those 3 were lost. I tried to reassign them, it seemed ok, but i still got "lost citizen". i saved, reloaded, and those 3 were lost again.
i am sure no other civ could have attacked the transport, so probably an issue with pathfinding or amount of citizens (total, or "on planets")
best regards and thanks for the fun game.