If the only thing you did is define properties of a liquid you probably have a units problem or some sort of other input error.  I suggest rebuilding the stream with the minimum amount of information you need and adding properties carefully 1 at a time until you reproduce the error or perhaps correct your previous error.

Memory overflow can occur in the stack or the heap when too much memory is used or the dimensions of an array are exceeded. Math over flow can occur in integers or floating point numbers that are too large or too small for the computer to handle.

If you wrote the subroutine that is failing, then you can debug it. For built in subprograms you input data may give the computer an impossible problem to compute. A quirk of ASPEN is that for some data error problems the FORTRAN routines can not recover when the incorrect data is replaced with the correct data. Sometimes you have to delete a component and reenter it.

I like to use the property estimation options to draw the chemical structure of the components including the ions and let the physical chemistry section try to calculate the properties. You could compare the physical properties you have to the ones estimated with ASPEN and maybe adjust some parameters to make it run.

You can read the run time log and try to learn at what point in the operation the fault occurred, or what property was being processed.