I'm trying to install EMC OpenMamage Plug-in for Nagios XI (5.6.2) running on a Centos 7.6 server.

In the configuration wizard, all the pre-requisite checks pass, but when I give it a valid IP address range, it fails with:

None of the IP addresses are reachable

which appears to be a pretty generic error.

Looking in the httpd error logs, the wizard generates the following two errors:

PHP Notice: Undefined index: requires_version in /usr/local/nagiosxi/html/config/monitoringwizard.php on line 0, referer: https://x.x.x.x/nagiosxi/config/monitoringwizard.php?&=

PHP Notice: Undefined variable: sel_host in /usr/local/nagiosxi/html/includes/configwizards/Dell_EMC_OM_NagiosXI_monitoring_wizard/Dell_EMC_OM_NagiosXI_monitoringwizard.inc.php on line 1096, referer: https://x.x.x.x/nagiosxi/config/monitoringwizard.php?update=1&nextstep=2&nsp=&wizard=Dell_EMC_OM_NagiosXI_monitoringwizard