I have a compiled JAR file, but it has a ton of classes that I don't have the source to. I only have the source code to a single class in the JAR, so I recompiled it (no changes) with javac in cmd prompt. Then I opened the JAR file in WinRAR and deleted the old main_class.class and updated it with my recompiled version.
Now every single time I start the program it says "could not find the main class: main_class. Program will exit." I am assuming that updating a JAR file with WinRAR doesn't work so are there any other ways to do it? Sorry, I'm pretty experienced with C++ but have never even touched Java.