Resolution: Cannot Reproduce
I get this error on the server:
Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Evaluation Error: Error while evaluating a Function Call, Function is_hash not defined despite being loaded! at /etc/puppet/environments/goosy/modules/apache/manifests/vhost.pp:410:9
(puppetforge module versions):
It worked fine before the upgrade to 3.6 series. AND I don't get the error when I do a Puppet apply just on the client.