diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/XtextGeneratorResourceSetInitializer.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/XtextGeneratorResourceSetInitializer.xtend
index 50d2b235f..ed99a0adf 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/XtextGeneratorResourceSetInitializer.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/XtextGeneratorResourceSetInitializer.xtend
@@ -19,6 +19,7 @@ import org.eclipse.emf.mwe.utils.StandaloneSetup
 import org.eclipse.xtext.ecore.EcoreSupportStandaloneSetup
 import org.eclipse.xtext.resource.IResourceServiceProvider
 import org.eclipse.xtext.util.internal.Log
+import org.eclipse.emf.ecore.EcorePackage
 
 /**
  * @noextend
@@ -30,6 +31,7 @@ class XtextGeneratorResourceSetInitializer {
 	public def void initialize(ResourceSet resourceSet, List<String> referencedResources) {
 		val delegate = new StandaloneSetup
 		delegate.resourceSet = resourceSet
+		resourceSet.packageRegistry.put(EcorePackage.eNS_URI, EcorePackage.eINSTANCE)
 		referencedResources.forEach[
 			loadResource(resourceSet)
 		]
diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/IdeaPluginGenerator.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/IdeaPluginGenerator.xtend
index 11456a2d3..32fe454d1 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/IdeaPluginGenerator.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/IdeaPluginGenerator.xtend
@@ -718,7 +718,7 @@ class IdeaPluginGenerator extends AbstractStubGeneratingFragment {
 		}
 		val classifier = type?.classifier
 		val feature = if(classifier instanceof EClass) classifier.getEStructuralFeature('name')
-		feature instanceof EAttribute && !feature.many && String.isAssignableFrom(feature.EType.instanceClass)
+		feature instanceof EAttribute && !feature.many && feature?.EType?.instanceClass != null && String.isAssignableFrom(feature.EType.instanceClass)
 	}
 	
 	def compileAbstractCompletionContributor(Grammar grammar) {
diff --git a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/AbstractInjectableValidator.java b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/AbstractInjectableValidator.java
index 75d467b7a..c0928d17d 100644
--- a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/AbstractInjectableValidator.java
+++ b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/AbstractInjectableValidator.java
@@ -73,6 +73,10 @@ public abstract class AbstractInjectableValidator implements EValidator {
 
 	protected abstract boolean internalValidate(EClass eClass, EObject eObject, DiagnosticChain diagnostics, Map<Object, Object> context);
 	
+	/**
+	 * If this validator is for an EPackage you want to use in multiple languages, 
+	 * this method should return false. Otherwise issues will be reported twice.
+	 */
 	public boolean isLanguageSpecific() {
 		return languageName != null;
 	}
diff --git a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/ComposedChecks.java b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/ComposedChecks.java
index 088069a07..db3cc1fa3 100644
--- a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/ComposedChecks.java
+++ b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/ComposedChecks.java
@@ -13,6 +13,11 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
+ * Annotation that allows to modularize the validator into multiple classes.
+ * 
+ * The listed validators should override the method {@link AbstractDeclarativeValidator#register(EValidatorRegistrar)}
+ * with an empty implementation otherwise all issues will be reported twice.
+ *  
  * @author Sebastian Zarnekow - Initial contribution and API
  */
 @Retention(RetentionPolicy.RUNTIME)
diff --git a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/CompositeEValidator.java b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/CompositeEValidator.java
index 7b2e61f6d..8d33e5b63 100644
--- a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/CompositeEValidator.java
+++ b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/validation/CompositeEValidator.java
@@ -215,6 +215,7 @@ public class CompositeEValidator implements EValidator {
 		CompositeEValidator result = new CompositeEValidator();
 		result.equalitySupportProvider = this.equalitySupportProvider;
 		result.useEObjectValidator = this.useEObjectValidator;
+		result.operationCanceledManager = this.operationCanceledManager;
 		if (this.contents != null) {
 			result.contents = Lists.newArrayList(this.contents);
 			this.contents = null;