After clonning (or installing) an Oracle Applications Release 12.0 or 12.1 instance on Linux 5, an error may occur while starting up the Apache service. The error would be this:

You are running adapcctl.sh version 120.6.12000000.4
Starting OPMN managed Oracle HTTP Server (OHS) instance ...
adapcctl.sh: exiting with status 204


Review the HTTP log file. It shows :

libraries: libdb.so.2: cannot open shared object file: No such file or directory


Soft link libdb.so.2 is missing.
To solve this issue,

- Shut down all Oracle Application Services

- As root user, create a soft link as follows:
# ln -s /usr/lib/libgdbm.so.2.0.0 /usr/lib/libdb.so.2

- Start up all Oracle Application Services