I'm very pleased to announce that the server has been updated to MC 1.11.2!
Version 1.0.4 of the official modded client has also been released, which simply updates Forge to be 1.11.2 compatible.
Please note, if you experience issues/crashes after updating the official modded client you should delete it from the launcher and reinstall it (being sure to back up single player worlds etc first) as they can develop strange issues when modpacks change MC versions.
Enjoy!