Online RPC server goes down

Hi,
We are upgrading natural from 2.1.3 to 3.1.6.
Our Broker is running on OS390 2.10 and its version is 6.1.1.
When the request comes to RPC server during adabas is closed, our online RPC server goes down. We get below message in CICS log.

NCI0020I CIC6 ASYN CICSUSER NAT2 05/137 22:46:36 NAT9969 NATURAL ESCAPED FROM ERROR LOOP - 2390 NAT3148

But we didn’t have same problem in natural 2.1.3.

any idea?

thanx,

Our Natural RPC server program is below.

  • EntireX Server asynchron task started.
    0030 * -------------------------------------------------------------------
    0040 DEFINE DATA LOCAL
    0050 01 STRANSID(A8) INIT <'NAT2 '> /* NATURAL TRANSACTION ID
    0060 01 SRV-DEF
    0070 02 SRV-NODE(A8) INIT <‘ETB148’> /* SERVER NODE
    0080 02 SRV-NAME(A8) INIT <‘SRV1’> /* SERVER NAME
    0090 02 TRACE (N1) INIT <0> /* TRACE LEVEL
    0100 02 USER-ID (A8) INIT <‘ETBSRV1’> /* ETB USER ID
    0110 02 MAX-BUFF(I4) INIT <30> /* RECEIVING BUFFER SIZE
    0120 02 NATPARMS(A50) INIT /* ADDITIONAL SESSION PARAM
    0130 <‘MENU=OFF,OUTDEST=CNSL,RPC=(RPCSIZE=64)’>
    0140 * <‘OUTDEST=CNSL,SENDER=CNSL,MENU=OFF’>
    0150 * <‘MENU=OFF,PRINTER=((10),AM=NAF,OPEN=ACC),BSIZE=64’>
    0160 * <‘MENU=OFF,BSIZE=64,RPC=(SIZE=40),OUTDEST=CNSL’>
    0170 01 LOGON-DATA
    0180 02 USER(A8) INIT <‘ETBhhhh’> /* NSC USER ID
    0190 02 PASSWD(A8) INIT <‘ETBSjjj’> /* NSC PASSWORD
    0200 02 LIB(A8) INIT <‘SYSRPC’> /* SERVER EXECUTION LIBRARY
    0210 END-DEFINE
    0220 CALLNAT ‘RPCSSRV’ STRANSID SRV-DEF LOGON-DATA
    0230 END

The error indicates adabas is not active.
Have all corrections been applied?
Is it possible to migrate to Natural 4.1.4 instead to go to a full supported version?
regards,
Michael