SINCE APPLYING ENFCICS APAR RO91406, CTS 5.4 STARTUP ABENDS WITH SYSTEM COMPLETION CODE=23E.
There is no evidence of CA-ACF2 initializing (PHASE) messages.
CICS TS 5.4 compatibility requires maintenance be applied to both ENFCICS and ACF2. Although the ENFCICS apar RO91406 was applied, the required ACF2 r16 maintenance, RO96890, was not.
Apply RO96890 and restart the CICS TS 5.4 region.