Variable is not recognized using python script in SOIL TEST application

I am trying to perform soil test using the parameters of modified cam clay. But one of the parameter 'lambda' is not recognized by PLAXIS SOIL TEST if run through python. Please find source code of it: 

from plxscripting.easy import *
s_t, g_t = new_server('localhost', 10101, password = 'Parik@1410')
g_t.Triaxial.Behaviour = "Undrained"
g_t.Triaxial.CellPressure = 100 
g_t.Material.lambda = 0.09
g_t.Material.kappa = 0.08
g_t.Material.nu = 0.25
g_t.Material.einit = 0.4
g_t.Material.M = 1.2
g_t.calculate(g_t.Triaxial)
print(g_t.Material.echo())

Error

I am using echo function also to find the variable and it is showing same name  "lambda" in output as shown below.

SoilMat named "Material"
  Comments: "Clay1"
  MaterialName: "Clay1"
  Colour: 11242654
  MaterialNumber: 0
  SoilModel: Modified Cam-Clay (8)
  UserDefinedIndex: 0
  DrainageType: Undrained (A) (1)
  DilatancyCutOff: False
  UndrainedBehaviour: Standard (0)
  InterfaceStrength: Rigid (0)
  InterfaceStiffness: Standard (0)
  ConsiderGapClosure: True
  K0PrimaryIsK0Secondary: True
  K0Determination: Automatic (1)
  CrossPermeability: Impermeable (0)
  Gref: 1050 kN/m²
  cref: 5 kN/m²
  phi: 30 °
  psi: 0 °
  verticalref: 0 m
  cinc: 0 kN/m²/m
  K0: 0 
  gammaUnsat: 15.5 kN/m³
  gammaSat: 17.5 kN/m³
  perm_primary_horizontal_axis: 0 m/day
  perm_vertical_axis: 0 m/day
  Rinter: 1 
  perm_secondary_horizontal_axis: 0 m/day
  TensileStrength: 0 kN/m²
  UDPower: 0 
  verticalinc: 0 
  Ginc: 0 kN/m²/m
  ninit: 0.285714285714286 
  nmin: 0 
  nmax: 0.999 
  gammaPore: 0 
  RayleighAlpha: 0 
  RayleighBeta: 0 
  ck: 1E15 
  UDPRef: 0 kN/m²
  einit: 0.4 
  emin: 0 
  emax: 998.999999999999 
  Dinter: 0 
  K0Primary: 1.61743558611769 
  K0Secondary: 1.61743558611769 
  OCR: 4.018 
  POP: 0 kN/m²
  SoilRatioSmall: 10 %
  SoilRatioMedium: 13 %
  SoilRatioLarge: 77 %
  PsiUnsat: 10000 m
  Sres: 0.0620347394540943 
  Ssat: 1 
  Gn: 1.3774 
  Ga: 3.83 1/m
  Gl: 1.25 
  PsiK: -1.06 m
  PsiS: -2.37 m
  HydraulicModel: 1 
  FlowDataModel: 0 
  DrainageConductivity1: 0 m³/day/m
  DrainageConductivity2: 0 m³/day/m
  InterfaceKn: 0 kN/m³
  InterfaceKs: 0 kN/m³
  DefaultValuesAdvanced: True
  nu: 0.25 
  DataSetFlow: Standard (0)
  SoilTypeFlow: Coarse (0)
  M50: 0 - 50 (0)
  UseDefaultsFlow: None (0)
  TablePsiPermSat: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
  SplinePsiPerm: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
  SplinePsiSat: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
  lambdaModified: 0.428571428571428 
  kappaModified: 0.0571428571428571 
  K0nc: 0.652920753140292 
  lambda: 0.6 
  kappa: 0.08 
  LambdaKappa: 7.5 
  M: 1.2 
  powerm: 1 
  Pref: 100 kN/m²

Help me with this query