This is the worse advice I have ever seen. This kind of 'doctoring' ends up with "take this pill, if it doesn't work come back'. (lets change that for loop to start with 1 instead of 0. problem still there ? hmm could be that equation is wrong...) How about this ? Take an X-Ray. See what is broken. Cut into the body, see what is broken. Same with software. The 'symptoms' are very diffuse and do not map 1 to 1 with the 'disease'. Use the debugger. Capture outputs at intermediate steps and evaluate them. Dig into the system to identify the actual problem, then fix that.