Is this on the release version of 3.3.1, and without mods? If so, please fill out a bug report here: https://forum.paradoxplaza.com/forum/forums/stellaris-bug-reports.941/
Originally posted by Lost Latios: Every time I try to start a game or save a new race the game crashes within the beta. Without the beta the game runs just as it should and I have no issues or crashes.