One hint regarding coils. If you inadvertently ask the software do something that would be physically impossible, such as winding a 1mm pitch coil from 2mm diameter wire, you will get a very vague error message. If that is the case, changing the settings to something realistically achievable will dispose of the error. No need to start the step over.
The interface does *not* wait for you to hit [OK]. It tries to follow every change of settings (which is good). So it is quite easy to get into that hole by setting a finer pitch *before* reducing the section size to suit.