I'm simulating a liquid-liquid extraction using a mixture of water and acetone as a feed stream and a solvent stream containing methyl isobutyl ketone. When I run the simulation I get the error message: Feed: phase equilibria calculation error. (T = 298.15 K, P = 101.325,00 Pa, MoleFracs = { 0,6, 0,4, 0, }). The data is from a sample file available on DWSIM.