I play an insane map sandbox game as the Torians at the moment (1.8 Mercenaries). In the current turn whenever focus switches to the fleet "Torian Fleet 43721" the game hangs and cannot be recovered (I waited as much as 15 minutes). It doesn't react to mouse and keyboard input anymore and must eventually be killed via Task Manager.
Ticket #RFY-861-35258, I attached a save game