Troubleshooting

Manual installation

In Github, go to Releases, latest, and download pLaunchControl.jar under Assets.
Copy the file pLaunchControl.jar to a folder code inside your sketch. This method makes the library available to an individual sketch.
Alternatively, if you intend to make the library available to all sketches, unzip the pLaunchControl.zip file to the libraries folder of your Processing installation (you can see the default sketchbook location in File -> Preferences). This method also makes Examples available.