Richards Mechanics: use of constitutive equation, MFront and failure simulation

Hello everyone,
I have a question related to the use of Mohr-Columb constitutive equation in HM process simulation.

I wanted to simulate the rainfall-induced landslide and want to use Mohr-Column constitutive equation to simulate the failure process. As far as I know and according to this documentation, to use Mohr-Column constitutive equation, need to use MFront. I have tried to use it with my model but it is giving some error (this model runs fine with LinearElasticIsotropic constitutive equation).

Input files: failuretest.zip (6.1 MB)

Thank you,
Laxman Kafle