InspIRCd v4.10.1 is now available, download it from the releases page.
The most notable changes in this release are:
Fixed the Windows binary containing the wrong version in the main executable.
Relaxed validation of usernames in USER as it broke some clients.
Whitelisted the +channel-context tag in the ircv3_ctctags module.
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.