The version I'm using is v8.3.4 for Windows. There is a conversion reactor (isothermic). One of the compounds is Nitrogen, it doesn't appear in any of the reactions, but in the outlet stream, Nitrogen is only 43% of the one that enter. There is another issue: The heat load obtained is NaN, must it not be 0? I attached a file of my simulation, that shows only the reactor with the problems. I appreciate you help to solve these problelms.