[ferret_users] Error Ferret crash; signal 11

[Nagarjuna Rao <dnrao.au@xxxxxxxxx>]

Dear All,

 I am (D.Nagarjuna Rao), using ferret latest version 6.84.Here with I am giving my script as follows.When I ran this script I got the following error.Does any body have any idea how do I resolve this.

  ==========================
  [nagarjuna@localhost win7]$ fer
     NOAA/PMEL TMAP
     FERRET v6.84 
     Linux 2.6.32-279.14.1.el6.x86_64 32-bit - 12/18/12
     25-Apr-13 11:19    

yes? go test_gradient.jnl
 set mem/size=1700
 Cached data cleared from memory
 use ncep_ncar_day_slp_1948-1960.nc
 let dpdx=slp[d=1,x=@ddc]*100
 let dpdy=slp[d=1,y=@ddc]*100
 save/append/file=slp_gradient.nc dpdx,dpdy
**ERROR Ferret crash; signal = 11

  ==========================

       Thanks in advance for any help,

Regards,

D.Nagarjuna Rao.