[Info-vax] MMS building FMS forms crashing on X86

[issinoho]

Hi, I know the information isn't a huge amount to go on but I'm hoping that I can get some pointers on tracking down this issue, whilst preserving IPR from a public forum.
We have a complex set of MMS scripts building libraries, shared images, executables and FMS forms. The code builds & works correctly on IA64.
My issue is when the process gets to the point of updating a forms library with a form whereupon it crashes out with an undefined function symbol error.
I can't see a way of getting more information about what is going on - perhaps experienced MMS and/or FMS developers could advise.
Anyway here is the log sequence (anonymized).

%MMS-I-GMTIMFND, Time for MY_USER_MENU.FLG is 23-JUL-1993 13:12:03.30
%MMS-I-GMTIMFND, Time for MY_USER_MENU.FRM is 17-NOV-1858 00:00:00.00
%MMS-I-GWKOLDNOD, Target MY_USER_MENU.FRM is older than MY_USER_MENU.FLG
%MMS-I-GWKWILLEX, MMS will try executing action line to update target MY_USER_MENU.FRM
FMS/TRANSLATE MY_USER_MENU.FLG
%MMS-I-GWKEXESTS, Status of executed command is %X18F29A91.
%MMS-I-GWKUPDONE, Completed update for target MY_USER_MENU.FRM
%MMS-I-GWKOLDNOD, Target MY$LIBS:USER_FMS_LIB.FLB(MY_USER_MENU=MY_USER_MENU.FRM) is older than MY_USER_MENU.FRM
%MMS-I-GWKWILLEX, MMS will try executing action line to update target MY$LIBS:USER_FMS_LIB.FLB(MY_USER_MENU=MY_USER_MENU.FRM)
%SYSTEM-F-CALLUNDEFSYM, Call using undefined function symbol
<CR><LF>  Improperly handled condition, image exit forced by last chance handle`
    Signal arguments:   Number = 0000000000000003
                        Name   = 0000000000003434
                                 000000008005D808
                                 000000000000001B
    Register dump:
    RAX = 0000000000000500  RDI = 0000000000100001  RSI = 0000000000003434
    RDX = 000000007ACDD740  RCX = 0000000000000000  R8  = 0000000000014008
	R9  = 0000000000000019  RBX = 000000007FFCF898  RBP = 000000007ACDDB90
    R10 = 000000000000000D  R11 = 000000000000000C  R12 = 000000007ACE5A38
    R13 = 0000000000000000  R14 = 000000007AEBA170  R15 = 00000000000DB010
    RIP = 000000008005D808  RSP = 000000007ACDDAD8  SS  = 000000000000001B

Any help would be appreciated. TIA.