diff --git a/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java b/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java
index e703d986cb3c..c706725aa36d 100644
--- a/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java
+++ b/platform/platform-api/src/com/intellij/openapi/actionSystem/DefaultActionGroup.java
@@ -9,10 +9,7 @@ import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.List;
+import java.util.*;
 
 /**
  * A default implementation of {@link ActionGroup}. Provides the ability
@@ -33,7 +30,8 @@ import java.util.List;
  */
 public class DefaultActionGroup extends ActionGroup {
   private static final Logger LOG = Logger.getInstance("#com.intellij.openapi.actionSystem.DefaultActionGroup");
-  private static final String CANT_ADD_ITSELF = "Cannot add a group to itself";
+  private static final String CANT_ADD_ITSELF = "Cannot add a group to itself: ";
+  private static final String CANT_ADD_ACTION_TWICE = "Cannot add an action twice: ";
   /**
    * Contains instances of AnAction
    */
@@ -76,11 +74,16 @@ public class DefaultActionGroup extends ActionGroup {
 
   private void addActions(@NotNull List<? extends AnAction> actions) {
     HashSet<Object> actionSet = new HashSet<>();
+    List<AnAction> uniqueActions = new ArrayList<>(actions.size());
     for (AnAction action : actions) {
-      if (action == this) throw new IllegalArgumentException(CANT_ADD_ITSELF);
-      if (!(action instanceof Separator) && !actionSet.add(action)) throw new ActionDuplicationException(action);
+      if (action == this) throw new IllegalArgumentException(CANT_ADD_ITSELF + action);
+      if (!(action instanceof Separator) && !actionSet.add(action)) {
+        LOG.error(CANT_ADD_ACTION_TWICE + action);
+        continue;
+      }
+      uniqueActions.add(action);
     }
-    mySortedChildren.addAll(actions);
+    mySortedChildren.addAll(uniqueActions);
   }
 
   /**
@@ -134,13 +137,11 @@ public class DefaultActionGroup extends ActionGroup {
 
   @NotNull
   public final ActionInGroup addAction(@NotNull AnAction action, @NotNull Constraints constraint, @NotNull ActionManager actionManager) {
-    if (action == this) throw new IllegalArgumentException(CANT_ADD_ITSELF);
+    if (action == this) throw new IllegalArgumentException(CANT_ADD_ITSELF + action);
     // Check that action isn't already registered
-    if (!(action instanceof Separator)) {
-      if (mySortedChildren.contains(action)) throw new ActionDuplicationException(action);
-      for (Pair<AnAction, Constraints> pair : myPairs) {
-        if (action.equals(pair.first)) throw new ActionDuplicationException(action);
-      }
+    if (!(action instanceof Separator) && containsAction(action)) {
+      LOG.error(CANT_ADD_ACTION_TWICE + action);
+      return new ActionInGroup(this, action);
     }
 
     constraint = (Constraints)constraint.clone();
@@ -163,6 +164,14 @@ public class DefaultActionGroup extends ActionGroup {
     return new ActionInGroup(this, action);
   }
 
+  private boolean containsAction(@NotNull AnAction action) {
+    if (mySortedChildren.contains(action)) return true;
+    for (Pair<AnAction, Constraints> pair : myPairs) {
+      if (action.equals(pair.first)) return true;
+    }
+    return false;
+  }
+
   private void actionAdded(@NotNull AnAction addedAction, @NotNull ActionManager actionManager) {
     String addedActionId = addedAction instanceof ActionStub ? ((ActionStub)addedAction).getId() : actionManager.getId(addedAction);
     if (addedActionId == null) {
@@ -406,12 +415,6 @@ public class DefaultActionGroup extends ActionGroup {
     add(Separator.create(separatorText));
   }
 
-  private static class ActionDuplicationException extends IllegalArgumentException {
-    ActionDuplicationException(@NotNull AnAction action) {
-      super("cannot add an action twice: " + action);
-    }
-  }
-
   /**
    * Creates an action group with specified template text. It is necessary to redefine template text if group contains
    * user specific data such as Project name, file name, etc