2502710 - Server crashes with empty stack trace files -- SAP IQ

Server crashes with empty stack trace files.

$ ls -l stktrc*
-rw-r--r-- 1 sybase sybase 0 Jun 25 21:31 stktrc-20170626-003125_1.iq
-rw-r--r-- 1 sybase sybase 0 Jun 26 07:09 stktrc-20170626-100941_1.iq

iqmsg shows that some user was disconnected when stack trace occured. After long timegap there is a cancellation request.

I. 06/26 00:31:25. 0000059566 Disconnect:  SA connHandle: 3493  SA connID: 24  IQ connID: 0000059566  User: user1
I. 06/26 00:31:26. 0000059671 Txn 116618206 0 116618206
I. 06/26 03:01:08. 0000000000 Cancellation request received:  SA connHandle: 2509  SA connID: 25  IQ connID: 0000057672  User: user2

I. 06/26 10:09:41. 0000000538 Disconnect:  SA connHandle: 61  SA connID: 32  IQ connID: 0000000538  User: user1
I. 06/26 10:11:00. 0000000022 Txn 116620883 0 116620883
I. 06/26 21:58:26. 0000000000 Cancellation request received:  SA connHandle: 30  SA connID: 31  IQ connID: 0000000169  User: user2

.stderr consist of following message

**************************************************
***   Sybase IQ Abort:
***      From:  st_connection.cxx:776
***      PID: 24545
***      Exception Location: 0x0x7ffcd74f5790
***      Error ID: 533,  Exception Type: hos_assertexception
***      Thread: 3612313344  (TID: 4, Original TID: 4)
***      Error #: 3,  O/S Error #: 0
**************************************************
   **  While handling one abort, caught signal 11, program abort on thread 3612313344 (TID 4)

SAP IQ 16.0

empty stacktrace , st_connection.cxx:776 , KBA , BC-SYB-IQ , Sybase IQ , Problem