Space or hallow

Hi can anyone please help me on how to fix this kind of issue , i pushed my slab up and it was fine from the start, then am placing my interior materials and i realised that my slab has a space/hallow in it.What is the course of it and how can i fixe it up. Because i can’t Ctr+Z to back the procedure when is too late for that.I started applying materials then i came across it.What can i do please.

Difficult to answer with a simple imagen, if you upload your model we can analize what is happening…


I mean, from your screenshot, it just looks to me you accidentally orbited your way inside your slab… If so, yeah, it happens.

SU does not work with filled solids but hollow volumes. Therefore you might accidentally find your way inside one.