diff --git a/platform/util/src/com/intellij/util/ArrayUtil.java b/platform/util/src/com/intellij/util/ArrayUtil.java
index d4f3a5e03e10..f0e447a8fe4d 100644
--- a/platform/util/src/com/intellij/util/ArrayUtil.java
+++ b/platform/util/src/com/intellij/util/ArrayUtil.java
@@ -296,7 +296,7 @@ public class ArrayUtil extends ArrayUtilRt {
    * @return new array
    */
   @NotNull
-  public static <T> T[] append(@NotNull final T[] src, final T element) {
+  public static <T> T[] append(@NotNull final T[] src, @Nullable final T element) {
     return append(src, element, (Class<T>)src.getClass().getComponentType());
   }
 
@@ -323,7 +323,7 @@ public class ArrayUtil extends ArrayUtilRt {
   }
 
   @NotNull
-  public static <T> T[] append(@NotNull T[] src, final T element, @NotNull Class<T> componentType) {
+  public static <T> T[] append(@NotNull T[] src, @Nullable final T element, @NotNull Class<T> componentType) {
     int length = src.length;
     T[] result = (T[])Array.newInstance(componentType, length + 1);
     System.arraycopy(src, 0, result, 0, length);
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/annotator/GroovyAnnotator.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/annotator/GroovyAnnotator.java
index e69c508ff779..9821ef6db9e1 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/annotator/GroovyAnnotator.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/annotator/GroovyAnnotator.java
@@ -906,9 +906,12 @@ public class GroovyAnnotator extends GroovyElementVisitor implements Annotator {
       }
       else {
         final PsiClass outerClass = clazz.getContainingClass();
-        if (com.intellij.psi.util.PsiUtil.isInnerClass(clazz) && !PsiUtil.hasEnclosingInstanceInScope(outerClass, newExpression, true)) {
-          Annotation annotation =
-            myHolder.createErrorAnnotation(refElement, GroovyBundle.message("cannot.reference.nonstatic", clazz.getQualifiedName()));
+        if (com.intellij.psi.util.PsiUtil.isInnerClass(clazz) &&
+            outerClass != null &&
+            !PsiUtil.hasEnclosingInstanceInScope(outerClass, newExpression, true)) {
+          String qname = clazz.getQualifiedName();
+          LOG.assertTrue(qname != null, clazz.getText());
+          Annotation annotation = myHolder.createErrorAnnotation(refElement, GroovyBundle.message("cannot.reference.nonstatic", qname));
           annotation.setTextAttributes(DefaultHighlighter.UNRESOLVED_ACCESS);
         }
       }
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/util/PsiUtil.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/util/PsiUtil.java
index 9533fc74e6cc..f8dc893854d1 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/util/PsiUtil.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/psi/util/PsiUtil.java
@@ -650,7 +650,7 @@ public class PsiUtil {
     return null;
   }
 
-  public static boolean mightBeLValue(GrExpression expr) {
+  public static boolean mightBeLValue(@Nullable GrExpression expr) {
     if (expr instanceof GrParenthesizedExpression) return mightBeLValue(((GrParenthesizedExpression)expr).getOperand());
 
     if (expr instanceof GrTupleExpression) return true;
@@ -785,7 +785,7 @@ public class PsiUtil {
     return false;
   }
 
-  public static boolean isRawType(PsiType type, PsiSubstitutor substitutor) {
+  public static boolean isRawType(@Nullable PsiType type, @NotNull PsiSubstitutor substitutor) {
     if (type instanceof PsiClassType) {
       final PsiClass returnClass = ((PsiClassType)type).resolve();
       if (returnClass instanceof PsiTypeParameter) {
@@ -857,7 +857,7 @@ public class PsiUtil {
     return expression instanceof GrReferenceExpression && methodName.equals(expression.getText().trim());
   }
 
-  public static boolean hasEnclosingInstanceInScope(PsiClass clazz, PsiElement scope, boolean isSuperClassAccepted) {
+  public static boolean hasEnclosingInstanceInScope(@NotNull PsiClass clazz, @Nullable PsiElement scope, boolean isSuperClassAccepted) {
     PsiElement place = scope;
     while (place != null && place != clazz && !(place instanceof PsiFile)) {
       if (place instanceof PsiClass) {
@@ -1091,7 +1091,9 @@ public class PsiUtil {
   private static String[] visibilityModifiers = new String[]{PsiModifier.PRIVATE, PsiModifier.PROTECTED, PsiModifier.PUBLIC};
 
   public static void escalateVisibility(PsiMember owner, PsiElement place) {
-    final String visibilityModifier = VisibilityUtil.getVisibilityModifier(owner.getModifierList());
+    PsiModifierList modifierList = owner.getModifierList();
+    LOG.assertTrue(modifierList != null);
+    final String visibilityModifier = VisibilityUtil.getVisibilityModifier(modifierList);
     int index;
     for (index = 0; index < visibilityModifiers.length; index++) {
       String modifier = visibilityModifiers[index];