How to analyze the code to fix its work

[HarrySto]

I am writing code for the “Time Tracker” application and one of the functions does not work, namely the display of the image. What’s wrong?
And yet, I want to analyze the entire code, maybe there are still errors that I don’t see. Is there some kind of automatic code analysis?

private void initPanel()
{
panel = new JPanel();{

}