There have been intermittent reports that Resource Import can replicate the imported resource under its own tree. This page explains how to identify the problem, and how to correct it.
Expand the Resource Tree, and verify that the resource is not replicated into itself:
It should like this:
If you don't notice that the resource is malformed and try to use it, you will encounter issues during read/writes via the resource, with improper join criteria.
Delete the resource, and re-import it.