The Collada specification explains that an instance\_controller can have skeleton entries to define which subset of a joint hierarchy shall be searched to find the joints, like:

```
<node>
  <instance_controller url="#skin">
    <skeleton>#root</skeleton>
    <bind_material>...</bind_material>
  </instance_controller>
</node>

```

But it does not tell what to do when no such indication is available. For example the `<authoring_tool>FBX COLLADA exporter</authoring_tool>` omits the skeleton:

```
<node>
  <instance_controller url="#skin">
    <bind_material>...</bind_material>
  </instance_controller>
</node>

```

When i parse such Collada code with the OpenCollada framework, then i get 

```
Sax FWL Error: Could not resolve sid ...

```

for every joint in the Joint hierarchy.
However Maya-2013 can import such collada with no issues. So is this a Bug in OpenCollada or a violation of the Collada specification from the FBX exporter ?