The base Nagios plugins suite includes the check_ping plugin for this use case: http://nagios-plugins.org/doc/man/check_ping.html Here's a few examples of the plugin's usage: https://linux.101hacks.com/unix/check-ping/ As far as how you turn that command execution into something Nagios can understan...

Here's the official documentation for using custom scripts/plugins with NCPA: https://support.nagios.com/kb/article/nagios-xi-using-scripts-plugins-with-ncpa-722.html It has a section which includes a sample Powershell script. Let us know if some part of that documentation is unclear or isn't workin...

Have you manually altered the database in any way recently? Restored an older version of XI to MySQL by hand? That sort of stuff? I would also make sure this machine isn't running out of disk space. That can often lead to database tables getting messed up. Try running the following script and see if...

Just one dude's opinion, but Nagios Core isn't really the right tool for managing updates/configuration of machines. You *could* do it, but that doesn't mean you *should* do it. Nagios Core is much better suited as a monitoring framework than a configuration management framework. I would highly reco...

Sure, but the actual implementation would depend on the authentication method being used (sometimes) as well as the operating system itself (all the time). Here's an older post I made where I do a Windows-based "logged in users" check via Powershell using and older NSClient++ version as th...

That's certainly an option, but I'm pretty sure all of the common Windows-based CPU checks (psutil/ NCPA as well I believe) leverage the exact same performance counters that NSClient++ is using in this case. I say that not to discourage you from doing your own investigation (because I could be wrong...

Do you know which version of NSClient++ is installed on the remote machine(s)? That's often a very important piece of information when troubleshooting NSClient++ problems.

You might try resetting the Windows performance counters on the remote machine(s) as a first step.

Per the win_package module docs, it is suggested to pass-in a product_id parameter when the package is not an MSI (it is an exe): https://docs.ansible.com/ansible/2.4/win_package_module.html You should be able to put practically whatever you want in there. I would suggest it be something conspicuous...

Here's a previous topic with a solution:
viewtopic.php?f=7&t=45003

EDIT: On the topic of altering the CGIs, here's a brief example I threw together a while back:
viewtopic.php?f=7&t=44185&p=222987#p222987

I'm still of the opinion that an incorrect replication strategy is to blame:
viewtopic.php?f=6&t=48577&p=251584#p251584