I'm trying to load Applets in a web browser over a network/Internet, and it's not working. I can do it locally, but not over a network/through the Internet. I have tried signatures on .JAR files containing the Applet, lowering my security settings with Java 7 to the lowest possible, hosting and running from different operating systems, all leading to the same result being that nothing works. I can load third party Applets, like the one from Oracle's official website using Java 8, as seen here: https://docs.oracle.com/javase/tutorial/deployment/applet/browser.html but I can't do it for myself with my own code. The most common error message I get is something along the lines of "class not found", and, “SecurityException, Permission denied: X” - X being the file path. I am posting in the security section because I think it may have something to do with security, but if not, I will post, or have my thread move elsewhere. If someone could give me step by step instructions to get Applets running in a web browser over a network/through the Internet, I would deeply appreciate it. I have been using BlueJ, JDK 7 and JDK 8, and Firefox 52.9.0 ESR.