Troubleshooting LaTeX isn’t always easy. Error messages can be opaque and in the wrong file, so it’s difficult to find out what the problem is.
One method to try is to create a new project, identical to the problematic one and narrow it down by removing a chunk and recompiling until it starts working. This can help narrow down the exact problem and often helps you see what the problem is. If you still can’t find the problem, then this pared down version, containing only the problematic code and the bare minimum of other code (like the \begin{document} command and so on), is very much appreciated by experienced users in the various forums aiming to help people with LaTeX because it makes life convenient for them: they know what you’re talking about and they can use your code without modifying it in any way to see what the problem is. If you don’t believe me, just see how many times they ask for a MWE when one isn’t given!
Nicola Talbot provides tips for obtaining LaTeX help via minimal working examples, including a section on understanding LaTeX’s (sometimes obscure) error messages.
If you get Crazy error: ! Argument of @sect has an extra }., help is at hand here on my website.
