Problem with derivative du/dt in Simulink

Hello, i have a problem with using the derivative of the speed of a machine in Simulink. The following message pops up: Unable to reduce the step size without violating a minimum step size of 2.2250738585072014E-308 at time 1.3034180890316852E-308. The simulation parameters of my model are on the attached image. Any ideas? Thx