New Assertion error converting model to j3o

HI Guys
I just started moving from jme 3.0 to 3.1 and im having to re-import all my animated assets to see if it fixes a different issue…

Im using the ogre exporter. Then using jme ide to convert to j30

With one of my assets im getting this error

java.lang.AssertionError
at com.jme3.scene.plugins.ogre.MeshLoader.pushBoneAssign(MeshLoader.java:579)
at com.jme3.scene.plugins.ogre.MeshLoader.startElement(MeshLoader.java:630) 

I had a look at the code and seems to be coming from and its

    private void pushBoneAssign(String vertIndex, String boneIndex, String weight) throws SAXException {
        int vert = parseInt(vertIndex);
        float w = parseFloat(weight);
        byte bone = (byte) parseInt(boneIndex);

        assert bone >= 0;
        assert vert >= 0 && vert < mesh.getVertexCount();

i think whats happening here is that because my boneIndex is 135 which is larger than 128 allowed for a byte… so its being read as a negative number.
Do you guys think this is a bug?
or are we not allowed to have large number bones for some reason?

Can any one recommend a fix or a workaround?