Hi everyone, I'm new to the forum so much appreciated if anyone can answer my question or help me resolve the issue I have with my model.

I have created this mould using shell feature, but after I have saved this files into STEP. I have then realised there are many broken faces which is not fixable. I have tried delete the surfaces using "delete face" tool but it doesn't work. Can someone please help if there are other ways to fix the surfaces.

Can anyone please suggest how I can fix the broken faces, thanks so much

I have attached the assembly file as well as the part file I used to create cavities on the mould.