Actor is black in editor mode, but in the game it's invisible

I ran into a very annoying problem. When i’m in editor mode, the actor is completely black, this is wierd because I put a material on it. But when i’m in preview mode, it’s invisible. Please help!

So, this is the problem, please help me.

it sounds like int the blueprint, in the rendering section, its set to invisible or hidden in game, and then in the game its casting a shadow and the lighting hasnt been rebuilt yet. or youre doing something weird to the material in the construction script.

I didn’t do any of these, so it’s very wierd, but thanks for trying to help.

Oh, and one more thing. It doesn’t matter what kind of material that I’m using, because it does this with every material. I think there’s something wrong with the emissive light