Why does this code work in UE and Suitelet scripts, but throws an unexpected error in a scheduled script??

I rarely use the xml module - there are better libraries for manipulating xml

using render module to craft the xml from a transaction, and then only using the xml module to verify against the XSD. Would look at a library if I was doing XML manipulation

It's shocking that such an issue would exist this far into the lifetime of the xml module. maybe it was an accidental regression?

that seems to be the case, I had a script calling xml.validate 50-90 times a day for 2 year that just started throwing the error 100% of the time one day in February