Why do I set stiff chemistry solver in mfix DEM and report an error after running? How can I successfully check stiff chemistry solver?
Did you try setting DES_EXPLICITLY_COUPLED as the message suggests?
The control for it is here:
If you don’t know where the control is for a particular variable, use the ‘keyword search’ feature:
If this does not help and you require further assistance please upload your project files (“Submit bug report”) from main menu.