https://support.nagios.com/kb/article.php?id=515
Scroll all the way down till you see Install check_nrpe Plugin Only. I recommend to not remove the old check_nrpe plugin, but create a new one for testing purposes. Follow the part that says
This will create another plugin in /usr/local/nagios/libexec/check_nrpe_v3.IF you wanted to install the plugin for testing purposes
Then in XI in Core Configurations Manager navigate to the commands menu and change the check_nrpe command to use the new plugin: Give this new plugin a try and let us know if you still see the same errors.