Do you use any mods? Try to disable them. If this not help and you playing on Windows try to do that: Open this directory: C:\Users\#WINDOWS_USERNAME#\AppData\Local\Uber Entertainment\ Rename "Planetary Annihilation" directory to something else. Try to run game again. It's will clean all your settings, but possible fix issue if it's related to settings.
Most likely that it. Try to verify game content though Steam or launcher. Such issue it's not something that might magically appear, but few times in past same behavior was related to corrupted game settings.
