Look at the two pictures. Before.jpg is before host, turn 16, After.jpg is after host, turn 17.
http://www.ljplus.ru/img4/s/h/shudoyama/before.JPG
http://www.ljplus.ru/img4/s/h/shudoyama/after.JPG
Selected armies simply dont move. We tried rehosting it - unsuccesfully, they stand still. As you can see, there is also no fighting going on in either starting or targeted province, which sometimes causes armies to stop, so we have no logical explaination other than 'bug'