CodeGenerator unable to generate class for grouping

Unable to generate java class file, for yang which contains these groupings:

grouping linkstate {
leaf distinguisher

{ type route-distinguisher; }

}

grouping link-state {
leaf local-ipv4-router-id

{ type ipv4-router-identifier; }

}

In console output:

[WARNING] Naming conflict for type 'org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.linkstate.rev150210.Linkstate': file with same name already exists and will not be generated.

This problem occurs in Windows environment, in linux all classes were generated properly.