Parting surface issue - mold design for injection molding

Hi guys,

I'm currently working on a scholar assignment on designing a model which will be manufactured using injection molding soon. As you can see it is a tiny plastic toycar.

So far everything went well. I'm at the point of generating the mold right now. The problem is though, when I try to make the parting surface, SW complains it failed to create surface due to geometric conditions. I am pretty mucht stuck at this point..

I hope you guys know how to fix this.

Thanks in advance!

SolidworksPlastics And Mold Design