Child Actor casting

So I want to fill a BP with information and when i do it it works, but when i save and exit i can not load up the project again it has a fatal error.

<ErrorMessage>Fatal error: [File:D:\Build\++UE4+Release-4.14+Compile\Sync\Engine\Source\Runtime\CoreUObject\Private\Templates\Casts.cpp] [Line: 11] &nl;Cast of LinkerPlaceholderExportObject /Game/Blueprints/FirstPersonBP/Blueprints/FirstPersonCharacter.FirstPersonCharacter_C:PauseMenu_GEN_VARIABLE.PauseMenu_GEN_VARIABLE_PauseMenu_C_CAT to Actor failed&nl;</ErrorMessage>

How can i work around this.