Hello,
can you try with the commit 6a3fc200b19500ddd6ed9a2236db6e21f777564a pushed to master? There were some improper conditions done when checking if the routing block exists. Few other issues related to returned code were fixed.
If all is ok, then it can be backported.
Cheers,
Daniel
Just for fun, I tried upgrading to the latest 4.4 HEAD (90be8b) and the crash behaviour did not change.
-- Daniel-Constantin Mierla http://www.asipto.com http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda Kamailio World Conference, Berlin, May 18-20, 2016 - http://www.kamailioworld.com