You should find additional diagnostics in the run time log. Maybe missing parameters in the property set, unmatched groups in the property estimation, impossible input or out put specifications.

Nonlinear implies something is recycled, either materials or energy. If there is  recycle stream try first to run with the recycle replaced by a feed stream and an output stream.

Also you can try running with a different feed composition, example one that is almost pure inert.

Time zero failure usually means incomplete or impossible data and/or configuration is supplied.  

Hi Jerry,

Well appreciated!  Thank you so much for your information.