I started a Galactic Conquest and played for many hours on it, saving as I went. I experienced one battle that was unusual because I was unable to select the units. After the battle, I was once again able to select units. A few battles later, I lost the ability to select units in battle, and stacking units on the world map would cause their disappearance. Every battle following also denied the selection of units. I was able to send off fleets to attack, and they would show up in a battle, but that was the extent of my control.
This seems to be related to our Empire at War mod Imperial Civil War rather than our Sins mod Ascendancy. Moved. ~ Slornie