Mold Design Tooling Split: Can't knit

I am trying to create a simple mold for a part in Solidworks, but I keep running into the issue during the tooling split where Solidworks says that it cannot knit the surfaces. I looked at a few other forum posts on this topic, and I still wasn't able to get it to work. I imagine that the issue is coming from how I made my shut off surfaces, but I'm not sure how to fix them.  Here's a copy of my part. I'd really appreciate any help you guys could give me!

SolidworksPlastics And Mold Design