UE4 keeps crashing on startup

While i have tried to change the default Value of a float var inside my Inventory Blueprint the Editor crashed. Since then the Editor keeps crashing on startup.

I have located the inventory uasset and deleted it from outside. After that the Engine i starting again. Then i have pulled in an older version of the Inventory from the Autosave Backup Folder and it worked but when i save everything and open up the engine again it crashes. I have also tried to create a complete new Blueprint and copied every function over by hand. But still the same issue.

Now i have installed the editor symbols for debugging and i get the following error

Fatal error: [File:D:\Build++UE4+Release-4.14+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Templates\Casts.cpp] [Line: 11]
Cast of LinkerPlaceholderExportObject /Game/Modules/Characters/Shared/BP_CharacterAbstract.BP_CharacterAbstract_C:BP_Inventory_GEN_VARIABLE.BP_Inventory_GEN_VARIABLE_BP_Inventory_C_CAT to Actor failed

Together with an enormous stacktrace from the engine itself. My project is a blueprint only project. Im not in to c++ programming so i have no idea what to do with this error.

The strange thing is that it is pointing to my character bp.

Pleas i need help. I dont know how to rescue my project since i have no backups (That i will change as soon i have fixed this problem)

So i pinned the error further down.

When i remove the Inventory Blueprint as component from the PlayerCharacter it works. Also when i place it in the level it works. But when i put it as sub component into any other blueprint it crashes on restart. (Not while compiling and also not on playing, everything in the same session works fine) When i restart and then try to access any bp that is releated to the inventory blueprint it crashes.

had the same problem, just reverting the blueprint in question to an earlier version from out version control fixed it (for you that would probably be the BP_CharacterAbstract).
However this stuff keeps coming up when I assign other child actors. Feels like there is some issue with the conversion to the new child actor template feature - super annoying because you start working on stuff and only know if it did cause a problem or not after restarting - and if it did you can only revert the files and lose your work =P

Same problem.

contacted EPIC via UDN, will keep you posted if there’s a solution

right on, it’s a bug in the engine but the EPIC guys already have a fix out:
https://issues.unrealengine.com/issue/UE-39323

if you compile the engine yourself it’s a simple fix, just go to ChildActorComponent.cpp and replace this line (line 88 for me):

if (ChildActorTemplate && ChildActorTemplate->GetOuter() != this && IsTemplate())

with the following one:

if (!Ar.IsPersistent() && ChildActorTemplate && ChildActorTemplate->GetOuter() != this && IsTemplate())

recompile, done.