org.eclipse.xtext.parsetree.reconstr.XtextSerializationException: Could not serialize cross reference from Grammar'org.xtext.example.mydsl.MyDsl'.metamodelDeclarations[0]->GeneratedMetamodel'myDsl'.ePackage to EPackage
	at org.eclipse.xtext.parsetree.reconstr.impl.AbstractParseTreeConstructor$AssignmentToken.serializeInternal(AbstractParseTreeConstructor.java:257)
	at org.eclipse.xtext.parsetree.reconstr.impl.AbstractParseTreeConstructor$AbstractToken.serialize(AbstractParseTreeConstructor.java:158)
	at org.eclipse.xtext.parsetree.reconstr.impl.AbstractParseTreeConstructor.write(AbstractParseTreeConstructor.java:771)
	at org.eclipse.xtext.parsetree.reconstr.impl.AbstractParseTreeConstructor.write(AbstractParseTreeConstructor.java:766)
	at org.eclipse.xtext.parsetree.reconstr.impl.AbstractParseTreeConstructor.write(AbstractParseTreeConstructor.java:766)
	at org.eclipse.xtext.parsetree.reconstr.impl.AbstractParseTreeConstructor.serializeSubtree(AbstractParseTreeConstructor.java:732)
	at org.eclipse.xtext.parsetree.reconstr.Serializer.serialize(Serializer.java:64)
	at org.eclipse.xtext.parsetree.reconstr.Serializer.serialize(Serializer.java:70)
	at org.eclipse.xtext.resource.XtextResource.doSave(XtextResource.java:342)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.save(ResourceImpl.java:1430)
	at org.eclipse.emf.ecore.resource.impl.ResourceImpl.save(ResourceImpl.java:999)

	public void serializeXtext(URI modelURI) {
		// load the xtext model to an xtextresourceset
		XtextResourceSet resourceSet = new XtextResourceSet();
		Resource xtextResource = resourceSet.getResource(modelURI, true);

		EcoreUtil2.resolveAll(xtextResource, null);
		EObject newMod = xtextResource.getContents().get(0);
		// path to xmi model
		String xmiPath = EditorUtils.getActiveXtextEditor().getResource().getProject().getFolder("product").getFullPath() + "/"
				+ "xtextResourceSerialization.xmi";
		// store in a xmi-resoure
		Resource xmiResource = resourceSet.createResource(URI.createURI(xmiPath));
		xmiResource.getContents().add(newMod);

		try {
			xmiResource.save(null);
		} catch (IOException e) {
			e.printStackTrace();

		}

	}

   private void XMItoXtext(URI uri){
                XtextResourceSet xrs = new XtextResourceSet();
		xrs.addLoadOption(XtextResource.OPTION_RESOLVE_ALL, Boolean.TRUE);

		// load the xmi resource
		Resource xmiRes = xrs.getResource(uri, true);
		// load the model from the xmi-resource
		EObject model= xmiRes.getContents().get(0);

		/*
		 * save the xmi-model to the xtext-resource
		 */
		// xtext file path
		String xtextFile = "test.xtext";
				

		System.out.println(xtextFile);
		// create the resource
		XtextResource a = (XtextResource) xrs.createResource(URI.createURI(xtextFile, true));

		// add the model to the xtext resource
		a.getContents().add(model);

		// save the new resource with the model
		try {
			a.save(null);
		} catch (IOException e) {
			e.printStackTrace();

		}
}

// loading the packages
		XtextPackage.eINSTANCE.eClass();
		EcorePackage.eINSTANCE.eClass();

		XtextResourceSet xrs = (XtextResourceSet) getGlobalXtextResource().getResourceSet();
		xrs.addLoadOption(XtextResource.OPTION_RESOLVE_ALL, Boolean.TRUE);

		// load the ecore resource
		Resource ecoreResource = xrs.getResource(URI.createURI(EcoreFactory.eINSTANCE.getEPackage().getNsURI()), true);
		ecoreResource.load(null);
		EcoreUtil2.resolveAll(ecoreResource);

		// load the xtext resource
		Resource xtextResource = xrs.getResource(URI.createURI(EcoreFactory.eINSTANCE.getEPackage().getNsURI()), true);
		xtextResource.load(null);
		EcoreUtil2.resolveAll(xtextResource);