The game was rebuilt with latest Unity (6000.2.12f1) to avoid the vulnerability they identified in older versions of the engine.
Engine update to Unity 6000.2.12f1
Source: Steam Community (opens in a new tab)
Build and release context
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 20817747 · public branch
Steam updated · First observed