CFD Online Discussion Forums - Error Messages: Self intersecting faces, Solid Part is not closed, Floating point.

Hi,
So I have been working on this project for a while. It is a thermal analysis of a thermo-forming/blow forming machine. The process includes preheating up a plastic tape(up to 200*C) , high temp tape moves on to the next stage which is the front of the male mould. Pressure of air is then applied to the opposite side of the tape blowing it into the mould and deforming its shape. I have the model of the tool and the deformed tape. Mould part is set to 75*C which also aids in cooling the tape and also the cycle time of the system happens within 500 miliseconds. I wanted to run a thermal analysis on the system to observe the following:
The effect in of the Preheat element on the mould (Preheat and mould is near each other)
The heat transfer between the tape and the mould during the cycle.

What I have done so far:
Import stp model to star, Created a subtract part of a block to the tool(this will be the external fluid part) modelling so that the effect of heat transfer between each part can be observed.
Boolean Imprint for contacts/interfaces between parts
After this part I have tried meshing it using a polyhedral mesher, surface remesher and prism layer for the fluid part. For the solid part I used polyhedral mesher and Surface remesher.

When I create the volume mesh I get the following error due to:

Self intersecting faces.
Solid part is not closed.
Error due to a floating point.

Any advice on how to deal with these errors?
Ps. Im able to mesh the parts without the fluid region that I added, but the heat transfer only affects the connected faces. So maybe there might be a way to model the heat transfer between parts without using a subtracted block as fluid interface between parts? Any suggestions?
Thank you