Since the dawn of time, or at least the dawn of UE4, there’s been a bug in UE4 which can be extremely damaging when it occurs, and where it occurs it always occurs again. I’ve seen a million answerhub threads about it but haven’t found one on the forums. Here are some of those answerhub threads:
Child blueprint class variables reset for some reason - UE4 AnswerHub
[Bug] Child blueprint values resetting on editor restart - UE4 AnswerHub
4.11 Child blueprint variables resetting to parent defaults - UE4 AnswerHub
There are more.
A lot of folks have this issue, but Epic have never been able to repro it (somehow?!?!?!). What happens is, one day you restart the editor and some or all of your child blueprints have had their variables reset to the parent’s defaults, so they’re just a clone of the parent blueprint now. Or, your actual child classes keep their overridden variables, but every instance of those child actors placed in any level lose their per-actor overridden variables. E.g, you put a bunch of doors in your level, and set some of them to locked and some to unlocked, but every time you restart the level they’re all unlocked because that was the class default. I guess this might be two separate issues (“actual child classes losing all overridden values and reverting to the parent values” and “instances of child actors in the level reverting to their default values”) but both only seem to happen on child blueprints and happen when the editor restarts.
For me, this issue is so massive that I absolutely won’t be able to ship my game before this is fixed. Unless I just never close the editor or something.
I have created an internet survey, god help me, to help gather more info on this garbage. There’d be more questions (does it only happen on editable variables, for one) but that site wants money for more than 10.
You can help by filling out the survey and posting in here about your experience of this issue! Maybe we can figure something out here since nobody’s been able to on Answerhub since 2014.