I have read the guidelines on how to post effective questions a priori.

The warning I quoted is the actual message minus the data element names in the Header hash that were appended to the end. I suppose I could have appended "element1, element2, ...".

I'd love to share the code so others can reproduce my problem but it's divided into multiple modules, with WSDLs, data pulled in from Excel worksheets, etc. The WSDLs are not something my employer would want on public forums.

Yes I could simplify the WSDL to hide the data structure, create inline sample data, simplify the code, and post it here in hopes of an answer. My approach however is to avoid that nontrivial effort and simply ask if someone might be familiar with this behavior or have more debugging insights.

Thanks for your suggestions. The keys of the hash are exact with no spurious characters.