I want to use http://code.google.com/p/bitlyj/ within my plugin, and I have added that as a referenced library. However, when I run the plugin, I get a NoClassDefFoundError. Obviously, this is caused by the JAR not being found at runtime, so how would I load the entire JAR? Thanks in advance. I put the jar bitlyj-2.0.0.jar in the main project folder, and I have this in my onEnable: Code: ((PluginClassLoader) this.getClassLoader()).addURL(new File("bitlyj-2.0.0.jar").toURI().toURL()); However, I still get the same error, even after restarting the server.