There is one small area of this model that I need to fill so that I do not have to create an extra slide in the plastic injection mold for nothing. If I put solid material into the area, even without linking to the model, the part goes to a single point in the area. I can get a surface to form in the area but still with problems and then cannot trim to knit and solidify. Are my delete faces in the area causing a problem or something else?

My general method of creating this part was:

Start with some preexisting geometry in this area(maybe another problem)

modify and build on it using surfacing

knit and solidify

add features that I could not generate with surfacing

shell

add more features

split into seperate pieces

add features to join seperate pieces in acutal assembly

save seperate pieces into seperate files.

I am stuck adding a lip to one half for my lip/groove assembly.