I know this is a year-old thread, but adding some info from my experience. Editing the config.xml worked to add my custom job to crontab and survived a reboot without taking down my unit. I think there may be some critical guidance missing from this post. There are a few characters that are commonly used in terminal commands that conflict with xml characters, for example less than (<), greater than (>), and ampersand (&), among a few others. These characters must be ‘escaped’ in order to live inside the xml file without ‘corrupting’ it. Even this forum has problems with these characters as evidenced by the missing less-than (<) symbols in previous posts. You can do this manually if you like (and have experience with xml escaping), but it’s probably much simpler to run it through a function to escape it automatically (to prevent human error if nothing else). One such tool is here:
Just paste your command line in there and copy the result to then paste into the <run> element as described above.
Hopes this helps someone else.
