Core Keeper's 1.3.0.7 security patch temporarily disables save-file sharing through mods on PC. The November 2 announcement identifies a vulnerability in Brotli, the library the game uses to compress saves. The developer says there is no indication it has been used to target Core Keeper players.

If a mod's save-sharing feature has stopped working after the update, that restriction is deliberate. The listed change concerns sharing save files through mods; the notice does not give a list of affected mods or a workaround.

Install the security update on PC rather than keeping an older build just to retain that feature. That is a precaution, not evidence that your own save or account has been compromised.

Restoring sharing depends on a Unity fix

The team hopes to enable mod save sharing again once the Unity engine has been patched to address the vulnerability. It has not supplied a restoration date. Do not treat this temporary restriction as confirmation that the underlying library issue is already fixed.

Our Core Keeper page collects the game's updates and practical resources.