Error: (use_ssl == true): Request packet version was invalid!
This error happens because of the version mismatches of NRPE in server and client. The NRPE version on server is either V3 or V4 and that on client is V2 in this case.
Previous versions of NRPE were limited to 1K in the response sent back to the plugin. In NRPE v3/v4 this has been increased up to 64K.
So in-order to resolve the issue, upgrade the NRPE in client machine to the same version that installed in server.
If it's not possible, use "-2" option along with nrpe command which will force the plugin to connect with v2 packets.
Here we need to update all the nrpe commands with this option.