Cannot solve Nonlinear iteration error

Hi,

i'm trying to run a simulation and I continuously get this error message: "Nonlinear iteration is not converging with step size reduced to hmin (3.19....E-13) at time xx.xxx. Try reducing the minimum step size and/or relax the relative error tolerance."

This error appears once I connect the Integrator block to my model, what I've already tried is: Increase the relative tolerance in the Solver section Change the min step size value Change the solver (now i'm using ode15s but I get the error with ode45 too) Disabled the Zero-crossing control Solver type = Variable-step

Has anybody any idea about how I could solve the problem?

Thanks a lot