Failed package on Windows

I have a project and much of the core functionality is in a plugin with C++ and blueprints.
I recently moved many assets from the main project to the plugin.
I have a blueprint structure called WorldDataRecord in the plugin.

If I ruin in the editor it all works fine.

When I try to package for windows I get many errors related to the struct. The very first error is

LogProperty: Error: FStructProperty::Serialize Loading: Property ‘StructProperty /Game/FirstPersonBP/Blueprints/FirstPersonCharacter.FirstPersonCharacter_C:ExecuteUbergraph_FirstPersonCharacter:K2Node_MakeStruct_WorldDataRecord’. Unknown structure.

I get similar errors in both the plugin and in the main (UI) program.

Any ideas? I’m at a loss.