VLE and FGIP calculations sometimes gets stuck at close to 0 mole fractions of one of the two solvents in a solvent mixture experiment

I noticed that, if one of the two solvents in a solvent mixture has a really low mole fraction (eg 1.634476222961322e-05) the VLE code seems to freeze (it says it's running but it still doesn't give an input after an hour, even though it normally runs in a couple of minutes).