I guess your /etc/puppetlabs/puppet/ssl on that machine has some wrong content? Or did you change ssldir in /etc/puppetlabs/puppet/puppet.conf? This seems more like a generic puppet issue, you may search for help in their forums. Also check the content of the CA cert on that machine openssl x509 -in /etc/puppetlabs/puppet/ssl/ca/ca_crt.pem -text. It should be matching the CA certificate configured for your puppetserver (puppet CA)