Allegro Symbol creation Error

 Hi,

I am using 16.6 to create my symbol. When I try to save it I receive below message and PCB editor doesn't save my new symbol anylonger:

(---------------------------------------------------------------------)
(                                                                     )
(    CREATE SYMBOL                                                    )
(                                                                     )
(    Drawing          : SO-4.dra                                      )
(    Software Version : 16.6P004                                      )
(    Date/Time        : Sun Jul 06 17:10:06 2014                      )
(                                                                     )
(---------------------------------------------------------------------)


Create Symbol of type: PACKAGE
    Directory = F:/OrcadProjects/Symbols
    Name      = so-4.psm
    User      = m
    Machine   = MR


Create symbol started.
 
 WARNING(SPMHA1-269): Shape has no segments. 66078400 
SHAPE        @66078400
1)  mask              = 40
2)  class             = 6 = ETCH
3)  subclass          = 0 = TOP
4)  branch_link       = 66078344
5)  branch_ptr        = 66078344
6)  symbol_ins_link   = 0
7)  first_connection       = 0
8)  first_void        = 0
9)  first_outline_seg = 0
10) first_patch_set   = 0
11) shape_fill        = 1
12) first_text        = 0
13) first_relation    = 0
14) extents.min       = (0 0)
15) extents.max       = (0 0)
16) prev_branch_item  = 66078344

WARNING(SPMHA1-269): Shape has no segments. 
ERROR(SPMHA1-291): Create symbol has been aborted.

Does anybody know the reason?

Thanks in advance,

Hossein