Playing my first game of ES2 as the United Federation, on turn 95 I just randomly lose. Reloading the previous auto-save changes my empire from the UF to a completely different empire all the way across the map, who lose on the next turn.

Version reported on the Menu is 1.0.54 S5 GOLD-Public.

Attached are the last three auto-saves.

 Save Files.zip

Thanks for the report Loki149! I tested your save file and it seems you lose because of bankruptcy. Maybe some notifications have been not displayed to inform you about it, but with the last patch (1.0.57), this problem should be fixed.