How to turn on line-numbered error messages in ASC file?

How can I turn on error reporting that tells me exactly on what line of my .asc file an error or warning has occurred?

I need this in order to debug why my fmscore is constantly segfaulting, presumably caused by my .asc file.

I know the .asc is causing the crash because when I removed a section of it, the crash suddenly stopped - but I can't figure out why it would crash at all, and it does so at unpredictable intervals, sometimes every few hours, sometimes every single time, ...

Any help appreciated, thanks!