The following message appeared after IPL which included starting OAM and CA1
CBR3615E Tape entry processing discontinued due to an installation exit (CBRUXENT) failure.
Release : 14.0
Component : CA 1 Tape Management
the CBRUXENT exit was disabled
CBRUXENT was enabled using "LI R,CBRUXENT"
See the following link for more information on reenabling the IBM OAM exits
https://www.ibm.com/support/knowledgecenter/SSLTBW_2.4.0/com.ibm.zos.v2r4.idao300/reset.htm