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Steam announcementStellarisSeptember 24, 2026

Stellaris 4.5.1 released (checksum 358e)

by 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).
  • 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!

Posted by the game’s developer or publisher to its Steam community hub and published by Valve through Steam’s public news API. Sifter reproduces it unedited and writes none of it.