InspIRCd v4.12.1 is now available, download it from the releases page.
The most notable changes in this release are:
Applied a patch to a vendored library to fix building on 32-bit x86 systems.
Fixed an issue with the v3 protocol compatibility layer where big channels with parameter modes set would not be synchronised correctly.
Fixed the httpd module rejecting HTTP requests that are split across multiple TCP packets.
No breaking configuration changes have been made since the v4.0.0 release. Please consult the list of breaking changes if you are upgrading from v3.
The full change log can be found on the docs site or on GitHub.