Stellaris 4.5.1 released (checksum 358e)
2026-09-24by Eladrin Hello, Stellaris community! We've updated Steam and GoG with a hotfix to address a few important issues. MS will follow as soon as it is possible. 4.5.1 ‘Cygnus’ Hotfix Release Notes Balance • A Synaptic Lathe built by nomads in another empire's system no longer changes ownership to the owner of the Starbase. • Note: This is a quality of life balance change. In a future patch we are likely to give the owner of a system with a Synaptic Lathe some means to deal with it. Bugfix • Fleet automation now follows the actions and options you select, instead of choosing for itself. • Removed the Harvesting Agreements Automation sub-menu setting, since the Trade Action has been removed • Disabled the auto-disengagement from battle when a ship didn't take part in combat for 15 days (ships disappearing from battle).
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• Note: This will return in a future release once we make it less overenthusiastic. Stability • Fixed a very common Out of Sync that would occur after the first day of Multiplayer Games where custom AI empires were spawning. We have taken the opportunity to bring in a number of other stability fixes that would otherwise have been in what’s now going to be 4.5.2: • Fixed a rare crash that could occur when joining an alliance. • Fixed a rare crash that could happen when a starbase automatically rebuilt its design after it changed level. • Fixed a crash during game startup caused by a technology that could not be resolved. • Fixed a crash during galaxy generation caused by a species with no assigned name data. • Fixed a crash that could occur when an empire joined a war. • Fixed a crash that could occur during first contact between empires. • Fixed a crash that could occur when accepting a federation law vote. • Fixed a crash that could occur when releasing a subject, or when a subject asked to be released. • Fixed a crash that could occur when a subject's overlord changed. • Fixed a crash that could occur when spending diplomatic weight on a galactic community resolution. • Fixed a rare crash when a waystation was destroyed after its controlling empire had already been eliminated. • Executing a spawn_natural_wormhole effect targeting an inexistent spatial reference object does not result in crashing the game any longer. Modding • Duplicate keys in a database now always log an error. Thank you for reporting these issues, and thank you for playing Stellaris!