WHY YOU CANNOT CREATE *.IN FILES

The reason that sometimes you could not create *.in files is that
you have not specified the project directory's full path name.
To do that you need to click on "simulation" and then "options" and specify the
full path name for both IC manager and Message files.  You must
do this when you first launch IC_Builder, before you do anything
else.  Moreover, when you enter IC_Builder again, you must do this
again, otherwise IC_Builder may place the generated *.in files
and ic.dat file in some buffer area under Windows and you may
never find them.  For example, suppose your project directory is
   c:\ic_builder\proj1
then you need to enter this after you select "simulation" and
then "options", as the path for both IC_Manager and Messages.
You also shoud select "simulation" and then "project" and
add a new file "x16.gra" and then click "okay", if you are
defining a new ic called x16.gra.  You will then click
the Export icon to generate x16.in under project directory proj1.