Why do I keep getting Singularity Error when ever I run my model?

I am trying to run my simulation model with step input and integrator. But whenever I try to run the model, I keep getting the same error each and every time I run the model. The error reads as "Derivative input 1 of 'non_linear_sim_m/Integrator5' at time 5.6352900311839029 is Inf or NaN. Stopping simulation. There may be a singularity in the solution. If not, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)". I went through the previous suggested solutions, even tough the error keeps showing up. Can anyone please help me with my problem? Thank you in advance.