As the title says, I've been trying to find an answer why both the tooling split and the shut-off surface give me the error: Cannot knit sheets. The shut off surface will work if I check the no fill option, however the tooling won't work, regardless of the Parting Surface. I've tried simplifying the split line by deleting some cuts in the model, but the result is the same. If anyone could find a way to help, I'd greatly appreciate it. (The model is based of a real world part)