Reiner,

Analysis: Timestep too small; time=0.000173642, timestep=1.25e-019:
trouble with node "n001"

I got the same or similar error message, when I tried to simulate a
square-root circuit model.
Of course, it is a big different between applications, but maybe good to
know, why
happened it. The reason was the negative value "under" sqrt, what is
imaginary number.
:) .

Peter