NRPE commands returning “UNKNOWN” after NSClient++ upgrade
Posted: Mon Mar 23, 2026 3:51 am
Hi all,
I’m running into an issue after upgrading NSClient++ on a few Windows servers (now on 0.5.x). Previously everything was working fine with NRPE checks, but now any external script I try to run returns “UNKNOWN: No handler for that command” or just “unknown command.”
I’ve double-checked my nsclient.ini and I do have CheckExternalScripts enabled, along with NRPEServer, and I’ve restarted the NSClient service multiple times. From what I’ve seen in similar cases, sometimes it’s just a config flag or syntax issue , but I can’t seem to spot what’s wrong in mine. The same scripts worked perfectly on an older version, so I’m guessing something changed in how modules or aliases are defined.
Has anyone run into this after upgrading? Do I need to explicitly define aliases or permissions differently in newer versions? Any help or example configs would be really appreciated.
I’m running into an issue after upgrading NSClient++ on a few Windows servers (now on 0.5.x). Previously everything was working fine with NRPE checks, but now any external script I try to run returns “UNKNOWN: No handler for that command” or just “unknown command.”
I’ve double-checked my nsclient.ini and I do have CheckExternalScripts enabled, along with NRPEServer, and I’ve restarted the NSClient service multiple times. From what I’ve seen in similar cases, sometimes it’s just a config flag or syntax issue , but I can’t seem to spot what’s wrong in mine. The same scripts worked perfectly on an older version, so I’m guessing something changed in how modules or aliases are defined.
Has anyone run into this after upgrading? Do I need to explicitly define aliases or permissions differently in newer versions? Any help or example configs would be really appreciated.