After migrating from 11g to 12C , XQuery function fn:doc started failing in one of the OSB project when trying to refer a static XML. After some research found out that it's happening only with XQuery version 1.0 not with 2004.
fn:doc("file://<filename>.xml")
Error Message:
Error executing the transformation: {http://www.w3.org/2005/xqt-errors}FODC0002: Error retrieving resource "file://<filename>.xml"
Solution:
Xquery implementation has been changed in 12C. So, to resolve this issue, give full path for the file
e.g.
fn:doc("file:///soa11g/soa1213/user_projects/domains/osb_domain/filename.xml")