Apple recently released iOS 11.2.6, which fixes an issue where using certain character sequences (Telugu) could cause apps to crash, and an issue where some third-party apps could fail to connect to external accessories
As with all iOS updates, we strongly suggest that you hold off on updating your devices until your aviation app and accessory developers have time to test compatibility with the new software.
Source: Ipad appsiOS Update Green Light program: iOS 11.2.6