My first R12 bug!

After our last dress rehearsal for applying R12, we encountered a problem with all of our Oracle Alerts giving us this error:

/s_u01/app/applmgr/<instance>/apps/apps_st/appl/alr/12.0.0/bin/ALECDC
Program was terminated by signal 11

This was really interesting since we were under the impression that nothing changed from our prior mock run, other than maybe some setup but nothing we knew would cause this.  Eventually we started asking questions while the DBAs were opening an SR with Oracle, and found out that we had applied the following patches:

13855823 - 1OFF:12373900:12.1.3:12.1.3:QREP1220.2:FND.RLNK:RELINK FAILED FOR MODULE FNDCPAS

14532468 - HIGH ENQ: TX - ROW LOCK CONTENTION ON FND_CONCURRENT_PROCESSES

10152652 - OPATCH to be applied to 10.1.2ORACLE HOME

Oracle came back and told us that they weren't sure of the reason, but we had to apply these patches to get our problem resolved:

Patch 13728376 - Alert fails with signal 11 error after password case sensitivity fix.

Patch 9908378 - RELEASE 12 BUG FOR SIGNAL 11 WITH ALPPWF
What is interesting in this case is our PROD password for the ALERT FNDassuming that the patches we applied directly affected this.  Additional testing showed that in another R12 instance without these patches applied, Oracle Alerts were working without issue and only after patch 10152652 was applied (with Alerts still working) then had 13855823 applied did Oracle Alerts get broken!