Error message BPXP028I for ABEND EC6-xxxxC04A can be seen in IBM Rational Developer for System z (RD/z) when doing TSO actions, invoking CARMA with CRASTART or invoking zUnit from within z/OS UNIX.
The problem only occurs if a product, being ISPF or RDz, is installed (or afterwards altered) using a non-zero UID.
Systems that installed ISPF or RD/z using a userid with a non-zero UID and that applied z/OS UNIX APAR OA41101. It also applies to systems where the z/OS UNIX files with the sticky on for these products were altered an no longer have UID 0 as owner.
Diagnosing the problem
z/OS UNIX APAR OA41101 alters default z/OS UNIX behavior for executing authorized MVS load modules through sticky bit, requiring the sticky bit files to be owned by UID 0 or be marked APF controlled.
Current versions of ISPF and RD/z do not have the APF bit set for these files, resulting in the "BPXP028I for ABEND EC6-xxxxC04A" message if the products were not installed by UID 0.
Resolving the problem
Set the APF bit manually, with these commands:
$ cd /usr/lpp/ispf/bin
$ extattr +a ISPZINT ISPZTSO
$ cd /usr/lpp/rdz/bin
$ extattr +a AZUTSTRN BWBTSOW CRASTART