yakindu/plugins/org.yakindu.sct.model.resource/plugin.xml

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.4"?>
<plugin>

   <!-- Resource Provider      -->
 <extension point="org.eclipse.xtext.extension_resourceServiceProvider">
        <resourceServiceProvider
           class="org.yakindu.sct.model.resource.SCTExecutableExtensionFactory:org.eclipse.xtext.ui.resource.generic.EmfResourceUIServiceProvider"
            uriExtension="sct">
        </resourceServiceProvider>
    </extension>

</plugin>