rostopic could not get message class, but rosmsg shows msg

edit

I have a custom message /adc_interface/EMGSignal. If I run rosmsg show EMGSignal it displays the message correctly. However, if I try to run rostopic echo /adc_interface/EMGSignals I get:

ERROR: Cannot load message class for [adc_interface/EMGSignal]. Are your messages built?

I also get a similar error when trying to use rqt_plot.

The message has been tested and used on Groovy on another computer. I am running Hydro on my computer.

I have run catkin_make. My .bashrc is:

source /opt/ros/hydro/setup.bash
export ROS_PACKAGE_PATH="/home/craig/Documents/workspace/551/project":$ROS_PACKAGE_PATH

I am new to Ros and may have some configuration/installation issues (I thought it would be fun to uninstall python from Linux Mint - it wasn't).

Additionally, running roswtf produces:

Loaded plugin tf.tfwtf
No package or stack in context
================================================================================
Static checks summary:

Found 1 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING You are missing core ROS Python modules: rosrelease -- 

Found 1 error(s).

ERROR Not all paths in ROS_PACKAGE_PATH [/home/craig/Documents/workspace/551/project:/opt/ros/hydro/share:/opt/ros/hydro/stacks] point to an existing directory: 
 * /opt/ros/hydro/stacks

================================================================================
Beginning tests of your ROS graph. These may take awhile...
analyzing graph...
... done analyzing graph
running graph rules...
... done running graph rules

Online checks summary:

Found 2 warning(s).
Warnings are things that may be just fine, but are sometimes at fault

WARNING The following node subscriptions are unconnected:
 * /rosout:
   * /rosout

WARNING The following nodes are unexpectedly connected:
 * unknown (http://gunstar:50711/)->/rosout (/rosout)