z/OS Agent crash: Agent STC abends with User Completion Codes U4042 and U4038

Document ID : KB000087271
Last Modified Date : 14/04/2018
Show Technical Document Details
Issue:
Error Message :
NO ACTIVE MODULE FOUND

The z/OS Agent crashes sporadically with User Completion Codes U4042 and U4038. Finally the Agent Started Task (STC) abends with a System Code S422.
 
This is due to heap memory damage. The Language Environment HEAP analyzer recognizes that an eye-catcher area of a HEAP block has been damaged and shuts down the agent STC with specific user completion codes.
 

Investigation

This issue can not be reproduced.  It will only occur when the Heap block on a system has been damaged and is dependant on the current operation of the Agent at that time.

Following are error messages and dump examples, which may help to identify the problem.

In the below example, the abend occurred after executing machine instruction 05EF (BRANCH AND LINK) in module UCXJM25 program §ST00020 at offset X'1FB8'.
 
14.03.53 STC48506  IEA995I SYMPTOM DUMP OUTPUT  111    111               USER COMPLETION CODE=4039 REASON CODE=00000000    111              TIME=14.03.50  SEQ=17003  CPU=0000  ASID=00C2    111              PSW AT TIME OF ERROR  078D1400   8A04C266  ILC 2  INTC 0D    111                NO ACTIVE MODULE FOUND    111                NAME=UNKNOWN    111                DATA AT PSW  0A04C260 - 00181610  0A0D58D0  D00498EC    111                GR 0: 00000000_84000000   1: 00000000_84000FC7    111                   2: 00000000_17BB5FC8   3: 00000000_40404040    111                   4: 00000000_0A040258   5: 00000000_0A04C266    111                   6: 00000000_178103E0   7: 00000000_17BAC030    111                   8: 00000000_17BB5FC8   9: 00000000_17BB5ADC    111                   A: 00000000_17BB692F   B: 00000000_8A04C188    111                   C: 00000000_17BADBF0   D: 00000000_17BB8A18    111                   E: 00000000_8A03F250   F: 7F4F1A00_00000000    111              END OF SYMPTOM DUMP
In the below example, the abend occurred after executing machine instruction 05EF (BRANCH AND LINK) in module UCXJM25 program §ST00011 at offset X'926'.
 
14.03.54 STC48506  IEA995I SYMPTOM DUMP OUTPUT  117    117               USER COMPLETION CODE=4042 REASON CODE=00000001    117              TIME=14.03.53  SEQ=17016  CPU=0000  ASID=00C2    117              PSW AT TIME OF ERROR  078D1400   89FFD09E  ILC 2  INTC 0D    117                NO ACTIVE MODULE FOUND    117                NAME=UNKNOWN    117                DATA AT PSW  09FFD098 - 00181610  0A0DA7F4  001C1811    117                GR 0: 00000000_84000000   1: 00000000_84000FCA    117                   2: 00000000_00000001   3: 00000000_89F7C000    117                   4: 00000000_17DD49C8   5: 00000000_00000001    117                   6: 00000000_178103E0   7: 00000000_09FFD062    117                   8: 00000000_80000000   9: 00000000_184FFCBC    117                   A: 00000000_00000001   B: 00000000_89FFCFC0    117                   C: 00000000_184FDBF0   D: 00000000_184FFAC0    117                   E: 00000000_8A15628E   F: 7F4F1A00_00000001    117              END OF SYMPTOM DUMP
 
 
Environment:
OS: MVS
OS Version: N/A
Cause:
Cause type:
Defect
Root Cause: z/OS agent crashes with user abend code U4042 due to user HEAP damage.
Resolution:
Update to a fix version listed below or a newer version if available.

Fix Status: Released

Fix Version(s):
Component(s): Agent MVS

Automation Engine 12.1.0 - Available
Automation Engine 12.0.2 - Available
Automation Engine 11.2.5 - Available
Automation Engine 11.1.6 - Available
Additional Information:
Workaround :
N/A