Here is an approach to identify the problem.

Start cutting out half of the source code, making sure that it is still syntactically correct (according to your opinion) and see if the error still persists. If it doesn't, backtrack and cut away the other half. Keep reducing your code like this until you have less than 10 lines that exhibits the error. The solution should then be apparent.

If the solution is not apparent, post the 10 lines here.