If you ever happened to encounter Document is Invalid error message for a Fedex shipping, here's why! 🔎
Document is Invalid is usually linked to a missing match between the first upload call and the actual shipping call.
What can I do to fix the issue? 🚑
As a first thing, verify here that the country you're shipping to supports ETD Documentation.
If it's not the case, check whether the same Document ID has been already used for other shipments.