I have this tray part that I am working on, In the past I have not utilized the mold tools in our tool designs but I thought that I would try it with this part. I have created my parting surfaces on the piecepart I went in and checked the draft using draft analysis then went to tooling split. Once in tooling split I created my sketch for the cavity and core blocks, and then entered the block size and checked the green check. and got an error Cannot Knit Sheets together. I am sure that I am doing something silly, Can anyone help? I have attached the part for reference.