Eheheh.. sorry about that.
Neither of us even remembers if we even got a message like that. I don't recall it at all to be honest.
What we've done is that we made the TMX (a blank one) in Tiled. Dragged that bugger into C2 and constructed the level in C2 to test things out. We replaced the tilemap that comes with the program before switching out those to the ones we are using (the demo tiles used 32x32 tiles like we do). The seams also happened when I tried using the demo tiles.
Again, very sorry for repeating questions. We're new with C2 and this just really had us scratching in our beards.