Hi Patrick,
I had a similar error a while ago, but I don't know if it was the exact same. It was caused by a import mapping that contained convert to microflow where text ('true' or 'false') was translated to a boolean.
Maybe this helps...
Regards,
Micha Friede
See this stackoverflow: https://stackoverflow.com/questions/36036700/org-json-jsonexception-jsonarray0-not-a-string
Either the JSON is not correct or there is a bug in the parsing of the JSON.
Regards,
Ronald