Re-install Redistributable Files:
Navigate to where the game is installed (default locations below):
64 bit operating system: C:\Program Files (x86)\Steam\steamapps\common\Sins of a Solar Empire Rebellion\_CommonRedist
Once there, please run ALL of the following files:
After, please reboot and try to run the game again.
^^^^ The _CommonRedist file does not exisit, therefore I can not find the mentioned files.