Dear @Emanuel.Rergis,
OK, I’m glad you got the model to run now.
There are many posts on this forum that provide guidance on how to select a suitable time step (DT). The time step requirement is dictated by the highest full-system natural frequencies of your model (with the standard rule of thumb being DT < 1/(10*f_max), which will depend on the system masses and stiffness. The full-system natural frequencies (including f_max in Hz) can be found through a linearization analysis followed by eigenanalysis (including MBC3 if the rotor is spinning with blade degrees of freedom enabled). There is also a balance between time step size (DT) and number of correction steps (NumCrctn); smaller DT can likely use smaller (or zero) NumCrctn, but setting NumCrctn to 1 or higher may allow you to use larger DT.
Best regards,