That looks like a plugin specific error, not necessarily something mis-configured on the Nagios Core side of things.

Can you share where you acquired this plugin, as well as the command and service definitions associated with this check?

Granted I haven't touched the official Dell stuff in a while, I didn't have much trouble making it work with Nagios Core. There's even a separate KB article for Nagios Core, and its almost identical to the XI one: https://www.dell.com/support/kbdoc/en-us/000178053/support-for-dell-emc-openmanage-plu...

"Cattle, not pets" and all that ;) benhank produced this a few years back, I dunno if it still works: https://exchange.nagios.org/directory/Utilities/Nagios-Uninstall--2F-Reinstall-script/details There was also an official script (and documentation) produced for uninstalling that used to ...

I'm not sure what you mean by NRPE plugins. Are you referring to the nagios-plugins suite? I don't think there's any plans to deprecate the nagios-plugins suite. You can run them as external plugins in NCPA just fine: https://www.nagios.org/ncpa/help.php#api-modules-plugins Which is a good thing bec...

I want to check 1 out of 4 drives on a Windows server at a different level to the other 3 using check_diskspace. Is it always the D: drive that needs the special thresholds? One option would be to string together one check that says "use these thresholds for all drives, except D:" and ano...

What version of check_esx3.pl are you using? There should be a -V / --version argument that the script accepts to print the version. You might try updating to the latest version to see if there's any performance gains: https://exchange.nagios.org/directory/Plugins/Operating-Systems/%2A-Virtual-Envir...

I'd definitely try a newer version of NSClient++. Something in the 0.5.2 line at least. Though it doesn't look like NSClient++ has had a release since 2018. Might try poking around the Centreon or NSClient++ forums: https://forum.centreon.com/ https://forums.nsclient.org/ Though it looks like the NS...

But, but I don't know exactly where to enter the command, in the Nagios command file or in the nsclient windows file? Which NSClient++ version are you running on the Windows machine? check_files is a built-in NSClient++ plugin: https://docs.nsclient.org/reference/windows/CheckDisk/ I'd suggest revi...

What version of NCPA are you running? You may need to use an older version like 1.8.1. Per the README : Older systems that have been supported by NCPA in the past: Ubuntu 12.04 using NCPA 2.1.4 Debian 7 using NCPA 2.1.4 OpenSUSE 11, 12, 13 using NCPA 2.1.4 AIX 6 with NCPA 2.1.1 CentOS / RHEL 5 using...

What steps did you follow to install the nagios-plugins dependencies? When I follow the official install instructions for Ubuntu on my Pi4, it "just works": https://support.nagios.com/kb/article/nagios-plugins-installing-nagios-plugins-from-source-569.html#Ubuntu ubuntu@ubuntu:~$ cat /etc/...