Plugin error Errno 13!?

[the8arewithme]

I tried to install Network Equipment Environmental Statistics plugin on Nagios Core on Ubuntu 14.04LTS and got

"(No output on stdout) stderr: /usr/bin/python: can't open file '/usr/local/nagios/libexec/check_env_stats.py': [Errno 13] Permission denied"

I've checked the permissions of the plugin and the directory mentioned in the error (Plugin is owned by Nagios in the Nagios group & the Dir is root). I've tried searching for the error/solution and can't find anything that works. Any help is greatly appreciated. If you need additional info I'll happily provide it, thanks in advance!

[jolson]

What command are you running that results in this error? How did you install this plugin? Thanks!