The error message you posted is not a standard Perl warning or error. Therefore, the cause of the message is not a direct result of your code. It originates from Text::Balanced, and if you are not using that module directly, then you must be using a module that uses that module (like Parse::RecDescent or similar).

It is impossible to advise you how to correct your code, without seeing the code, but I would not suggest you post your 3000 lines here, so you are going to have to do some detective work and come up with a few lines of code that produce the same error. If you haven't solved it by the time you have reduce your code to < 30 lines, then post the lines that produce the problem and someone will be able to help you.