Apache2 update error after update

opensuse 42.2

After a recent of Apache2 update by zypper, a series of messages were emitted:

Output of apache2-2.4.23-8.12.1.x86_64.rpm %posttrans script:
    /usr/share/apache2/apache-22-24-upgrade: line 6: a2enmod: command not found
...more of the same...

a2enmod exists in the system at </usr/sbin/a2enmod>. Both user and root can find the app although the user invocation complains about it being in /usr/sbin/.

Is a2enmod important? (The local websites continue to work.)
Does zypper spawn a non-root process to run a2enmod? If so, what changes are needed so it can run a2enmod?