Floating point exception
 

Hi .. i am doing a 2d simulation of pcm melting with a alumunium fin inside it .. mesh size is 0.5mm for pcm enclosure and fin and 3mm for plexiglass.
Fluent settings
Flow is laminar
Unsteady
Gravity =-9.81 m/s
Solidifcation and energy eq is turned on
Pcm properties
Lauric acid
Density: boussinesq : 912.5
Cp :2285
Thermal conducitivity :0.14
Viscosity is piecewise-linear
(Temp= 316.65 value =0.008323)
Thermal expansion coefficient =0.0008
Pure solvent melting heat =187210
Solidus temp =316.65K
Melting temp= 321.35K
Fin = alumunium
Plexiglass
Density =1180
Cp=1464
Thermal conducitivity =0.18
Cell Boindary condition
Pcm operating temp =319.15K
Boundary conditions
Fin right and pcm right (both has temp of 343.15K)
Remaining side of pcn is the plexiglass
Methods
1 Scheme =PISO
2 Pressure is PRESTO
Controls
0.75 for pressure and momentum
0.5 for liq frac
Residuals
Continuity,x and y= 1e-6
Energy =1e-9
Intialization
From all zones at a temp of 298.15K
Temp step size = 0.1s
Ietrations= 120
The issue i am facing is the floating point exception : temperature