Rob
Ansys Employee

Tolerance should be left alone, it effects the accuracy and default should be good for most cases. 

If a pathline is aborted it's becuase you've dropped the tolerance too far  https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v222/en/flu_ug/flu_ug_sec_discrete_post.html%23x1-159800024.11.2    With default tolerance and 10000 steps how does it look?