So as in the title, whenever I try to "Run Puppet" from Foreman I get the following error in the GUI.
This was all due to, in the beginning a configuration error, where activemq needed to be set up. Once that was determined and set up correctly, I then began getting an ERF12-4252 error, that was corresponding to this error message below in the foreman-proxy logs.
W, [2016-10-02T11:12:17.782288 #1796] WARN -- : Non-null exit code when executing '["/usr/bin/sudo", "-u", "root", "/opt/puppetlabs/bin/mco", "puppet", "runonce", "-I", ""]' E, [2016-10-02T11:12:17.782431 #1796] ERROR -- : Failed puppet run: Check Log files I, [2016-10-02T11:12:17.782622 #1796] INFO -- : x.x.x.x - - [02/Oct/2016:11:12:17 -0400] "POST /puppet/run HTTP/1.1" 500 34 0.0054
I was able to finally figure out where the problem was despite the logs being very vague, by adding a shell to the foreman-proxy user, and attempting to run that exact command from the CLI instead of through the Foreman GUI.
Marking this as solved.