We are trying to upload a binary file to Oracle Fusion Cloud using ErpIntegrationService (Fusion). Currently the file is Base64 encoded.
According to session logs the upload process works and we receive the SOAP Reponse XML. After this we get errors:
ERROR : HIER_28056 : XML Reader: Error [InvalidDocumentStructure] occurred while parsing:[Error at (file EMPTY, line 1, char 1 ): Invalid document structure.]; line number ; column number 
ERROR : HIER_28058 : XML Reader Error
After discussing this with Informatica Support they tell me that the SOAP Response is not "plain" XML, but rather XOP+XML. Informatica does not support this nor do they have plans on supporting it. The SOAP XOP+XML response in this case does not actually contain any "XOP" parts, it is plain XML, but it is labeled as "Application/XOP+XML"
Has anyone had success with communicating with Oracle Fusion ? Or know of a workaround to be able to read these SOAP XOP+XML responses ?
We are using PC9.5.0 with a standard license.
To answer my own question. It is not possible to do this with standard Informatica tools. Using a Java transformation we were able to get this done.