Having worked in tech support: level 3 (Devs) should have described their source code structure to level 2, and let them access it when they needed it.

You don’t need a complete diagnosis if you can spit out enough debug info that says, “oops shat the bed while working with this flight plan”, then the support people can remove the one that’s causing you to fail, restart the system, and tell ATC to route that one manually.