Having a reference error or something

The error I get is “Default Value’/Engine/Transient.REINST_turretData_C_1’ for {magnifying glass]Target is invalid. ‘/Engine/Transient.REINST_turretData_C_1 isn’t a turretData_C(specified on pin self)’”

What does this mean? I’m getting this error on my Turret Blueprint, where I use the functions to get turretdata based on an enum. turretData is a function library. I call say, getTurretArmor with an enum, and it returns a set of variables depending on which enum I’ve passed in. I havent touched any of this blueprint code in weeks. I have been working on my UMG widgets get information from the turret blueprint, when this error popped up.

I’ve tried using the reference tree, but it only lists a single BP, and doesnt seem to do anything. I’ve gotten similar bugs on other blueprints, but they usually seem to clear themselves. But since I started working on being able to spawn actors through a UMG widget, the game preview is crashing the editor every time I exit the game. I cant continue forward without fixing this…

Running 4.5.1, all code is blueprints only.