Error in modeling a fluid flow and heat transfer in a 3D box

Hello Sir Amir Fadil

I am trying to simulate a 3D NITF Problem by heating up the air inside a box and observe the thermal transfer and fluid flow.

My intention of doing this hypothetical problem is to try this to reach this trial into convergence so that I could use this in simulating the drying of some agricultural product.

The material properties of the air is composed of piecewise and analytic functions in terms mostly of temperature, pressure and area.
However, an error occured as:

''Failed to evaluate variable Jacobian.''
- Variable: pA
- Geometry: 1
- Domain: 1 2 4

I tried the same set up and a different fluid (WATER) with material properties similarly composed of piecewise and interpolation functions and there was no error.

I tried searching for the cause of the error but seems i don't have enough knowledge and the expertise to find it.

Could you please have a look at it and help me find the cause of the error.

Attached is the file.

Thank you very much.

Jonathan