*-- Is the array declared? You don't have to, but it's always a good idea.
   LOCAL ARRAY aEmployees[1]
   *-- 

   select SEMPCODE,SNAME from EMPINFO where &cFilter into array aEmployees
   with ThisForm.lstEmployees
        .Clear

        if type('aEmployees')='U'
           wait 'No Employees found matching the selection criteria';
                window timeout 5
           return
        endif

        *-- Did this line really work?
        *-- nTotalItems=(alen('aEmployees')/2)
        nTotalItems = alen(aEmployees,1)

        for x = 1 to nTotalItems
            .AddItem((aEmployees(x,1)),x,1)   && Either of these
            .ListItem(x,2)=(aEmployees(x,2))  && two lines cause the error
        next
        .Value=.List(1)
        .Refresh
   endwith