I’ve submitted a fix for this bug in this pull request:
https://github.com/EpicGames/UnrealEngine/pull/2777
Those working with TickIntervals may also be interested in this associated pull request – https://github.com/EpicGames/UnrealEngine/pull/2776 – which addresses the issue brought up here: AllEnabledTickFunctions.Remove Crashes 4.12 - Programming & Scripting - Epic Developer Community Forums