I think I recognize that message, it comes from Eclipse. You didn't mention that you were using Eclipse, and that would have been useful information. And are you running your code in Debug mode? Because that message appears when the debugger tries to step into code for which you don't have the source. It doesn't particularly say anything about your actual code, not even that there's an error.
Joined: Apr 30, 2013
You are correct. I am using Eclipse, and the code runs fine when not in debug mode.
How can I fix this? I am a newbie, so please keep it as simple as possible.
You do not need to fix that error at all. What it means is that you are using a class whose bytecode is available but not its text code. When you are debugging, Eclipse can show the original code and the line number where an Exception occurred. Much code is only supplied in .jar files, which only contain the bytecode, so that Exception information is not available.