There are few differences between apachectl.in from 2.4.6 and apachectl from 2.4.23-DR3.
Most important is variable ROOTDIR that is missing in 2.4.23-DR3.
Variable is responsible for informing jbcs where the root dir of jbcs is.
Without is jbcs is looking to /opt/jbcs-httpd24-2.4.

Reproduce
1. install jbcs outside /opt, make sure that there is no installation of jbcs in /opt
2. start httpd (./apachectl start)
Expected -
httpd starts
Now -
httpd writes error message and not starts