Monitoring for errors

[skyraker]

I'm getting tired of having a problem with the addon I'm working where I get an UI error states 'function expected instead of nil'. It doesn't give me any indication on where the error is. I know it typically means I missed some parameter to a function call that was expecting one, but between my last working version and the one with the error I only added function calls that do not take parameters.

Am I missing some way to get a better idea about what the error is about?