Many users crash the simulator by turning on the full kinetic reactor immediately. The EHY2102 "Unit O" approach teaches a staged methodology:

One of the biggest headaches in simulation is getting the math to solve. Petroleum columns are mathematically stiff and difficult to converge. EHY2102 methodologies teach the correct initialization techniques—ensuring that your simulation doesn't crash when you try to run it.

: Understand the workflow for transferring HYSYS data to Aspen PIMS for updating refinery planning models. Key Refinery Unit Operations & Models