After using my cultural influence to take the last Terran planets all of their fleets, shipyards, and starbases converted to pirates except three of the Terran starbases which became my own. Now several of my planets and a few starbases have pirate ships in orbit of them. Once I end the turn the pirates invade a planet and the game crashes. I tried decommissioning all of the starbases but the game still crashes so I have to assume it has something to do with the pirates invading a planet that already has their ships in orbit. Interestingly, once I reloaded a previous auto save all of the destroyed races came up in the diplomacy again for one turn and I could trade technology for them. Talking to the destroyed races however caused some instability but I was able to get a large amount of money from them. Eventually to get around the issue of the game crashing I bought off all of the Terran ships before their civilization became pirates.