diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/SWF.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/SWF.java
index c34b4c9c9..b2435d62f 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/SWF.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/SWF.java
@@ -360,7 +360,7 @@ public final class SWF implements SWFContainerItem, Timelined {
         }
     }
 
-    private void parseCharacters(List<ContainerItem> list) {
+    private void parseCharacters(List<? extends ContainerItem> list) {
         for (ContainerItem t : list) {
             if (t instanceof CharacterTag) {
                 characters.put(((CharacterTag) t).getCharacterId(), (CharacterTag) t);
@@ -683,16 +683,14 @@ public final class SWF implements SWFContainerItem, Timelined {
     }
 
     private void findABCTags() {
-        List<ContainerItem> objs = new ArrayList<>(tags.size());
-        objs.addAll(tags);
 
         ArrayList<ABCContainerTag> newAbcList = new ArrayList<>();
-        getABCTags(objs, newAbcList);
+        getABCTags(tags, newAbcList);
         isAS3 = (fileAttributes != null && fileAttributes.actionScript3) || (fileAttributes == null && !newAbcList.isEmpty());
         abcList = newAbcList;
     }
 
-    private static void getABCTags(List<ContainerItem> list, List<ABCContainerTag> actionScripts) {
+    private static void getABCTags(List<? extends ContainerItem> list, List<ABCContainerTag> actionScripts) {
         for (ContainerItem t : list) {
             if (t instanceof Container) {
                 getABCTags(((Container) t).getSubItems(), actionScripts);
@@ -1782,7 +1780,7 @@ public final class SWF implements SWFContainerItem, Timelined {
     }
     private HashMap<ASMSource, ActionList> actionsMap = new HashMap<>();
 
-    private void getVariables(List<ContainerItem> objs, String path) throws InterruptedException {
+    private void getVariables(List<? extends ContainerItem> objs, String path) throws InterruptedException {
         List<String> processed = new ArrayList<>();
         for (ContainerItem o : objs) {
             if (o instanceof ASMSource) {
@@ -1864,10 +1862,8 @@ public final class SWF implements SWFContainerItem, Timelined {
         allVariableNames = new ArrayList<>();
         allStrings = new HashMap<>();
 
-        List<ContainerItem> objs = new ArrayList<>();
         int ret = 0;
-        objs.addAll(tags);
-        getVariables(objs, "");
+        getVariables(tags, "");
         informListeners("rename", "");
         int fc = 0;
         for (MyEntry<DirectValueActionItem, ConstantPool> it : allVariableNames) {
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/MethodBody.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/MethodBody.java
index 0a310f206..fe2fceada 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/MethodBody.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/abc/types/MethodBody.java
@@ -15,7 +15,6 @@
  * License along with this library. */
 package com.jpexs.decompiler.flash.abc.types;
 
-import com.jpexs.decompiler.flash.AppResources;
 import com.jpexs.decompiler.flash.abc.ABC;
 import com.jpexs.decompiler.flash.abc.ABCInputStream;
 import com.jpexs.decompiler.flash.abc.avm2.AVM2Code;
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineButton2Tag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineButton2Tag.java
index a74da76cf..606ef1666 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineButton2Tag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineButton2Tag.java
@@ -25,7 +25,6 @@ import com.jpexs.decompiler.flash.tags.base.BoundedTag;
 import com.jpexs.decompiler.flash.tags.base.ButtonTag;
 import com.jpexs.decompiler.flash.tags.base.CharacterTag;
 import com.jpexs.decompiler.flash.tags.base.Container;
-import com.jpexs.decompiler.flash.tags.base.ContainerItem;
 import com.jpexs.decompiler.flash.timeline.DepthState;
 import com.jpexs.decompiler.flash.timeline.Frame;
 import com.jpexs.decompiler.flash.timeline.Timeline;
@@ -168,10 +167,8 @@ public class DefineButton2Tag extends ButtonTag implements Container {
      * @return List of sub-items
      */
     @Override
-    public List<ContainerItem> getSubItems() {
-        List<ContainerItem> ret = new ArrayList<>();
-        ret.addAll(actions);
-        return ret;
+    public List<BUTTONCONDACTION> getSubItems() {
+        return actions;
     }
 
     /**
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineSpriteTag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineSpriteTag.java
index 55789e057..76e4fd647 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineSpriteTag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/DefineSpriteTag.java
@@ -27,7 +27,6 @@ import com.jpexs.decompiler.flash.tags.base.BoundedTag;
 import com.jpexs.decompiler.flash.tags.base.CharacterIdTag;
 import com.jpexs.decompiler.flash.tags.base.CharacterTag;
 import com.jpexs.decompiler.flash.tags.base.Container;
-import com.jpexs.decompiler.flash.tags.base.ContainerItem;
 import com.jpexs.decompiler.flash.tags.base.DrawableTag;
 import com.jpexs.decompiler.flash.tags.base.PlaceObjectTypeTag;
 import com.jpexs.decompiler.flash.timeline.DepthState;
@@ -257,10 +256,8 @@ public class DefineSpriteTag extends CharacterTag implements Container, Drawable
      * @return List of sub-items
      */
     @Override
-    public List<ContainerItem> getSubItems() {
-        List<ContainerItem> ret = new ArrayList<>();
-        ret.addAll(subTags);
-        return ret;
+    public List<Tag> getSubItems() {
+        return subTags;
     }
 
     /**
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject2Tag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject2Tag.java
index 58f6af895..5658a4849 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject2Tag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject2Tag.java
@@ -23,9 +23,9 @@ import com.jpexs.decompiler.flash.abc.CopyOutputStream;
 import com.jpexs.decompiler.flash.configuration.Configuration;
 import com.jpexs.decompiler.flash.tags.base.CharacterIdTag;
 import com.jpexs.decompiler.flash.tags.base.Container;
-import com.jpexs.decompiler.flash.tags.base.ContainerItem;
 import com.jpexs.decompiler.flash.tags.base.PlaceObjectTypeTag;
 import com.jpexs.decompiler.flash.types.BasicType;
+import com.jpexs.decompiler.flash.types.CLIPACTIONRECORD;
 import com.jpexs.decompiler.flash.types.CLIPACTIONS;
 import com.jpexs.decompiler.flash.types.CXFORMWITHALPHA;
 import com.jpexs.decompiler.flash.types.ColorTransform;
@@ -269,12 +269,11 @@ public class PlaceObject2Tag extends CharacterIdTag implements Container, PlaceO
      * @return List of sub-items
      */
     @Override
-    public List<ContainerItem> getSubItems() {
-        List<ContainerItem> ret = new ArrayList<>();
+    public List<CLIPACTIONRECORD> getSubItems() {
         if (placeFlagHasClipActions) {
-            ret.addAll(clipActions.clipActionRecords);
+            return clipActions.clipActionRecords;
         }
-        return ret;
+        return new ArrayList<>();
     }
 
     /**
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject3Tag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject3Tag.java
index 0efeb52f8..fe3f2d49c 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject3Tag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject3Tag.java
@@ -24,9 +24,9 @@ import com.jpexs.decompiler.flash.abc.CopyOutputStream;
 import com.jpexs.decompiler.flash.configuration.Configuration;
 import com.jpexs.decompiler.flash.tags.base.CharacterIdTag;
 import com.jpexs.decompiler.flash.tags.base.Container;
-import com.jpexs.decompiler.flash.tags.base.ContainerItem;
 import com.jpexs.decompiler.flash.tags.base.PlaceObjectTypeTag;
 import com.jpexs.decompiler.flash.types.BasicType;
+import com.jpexs.decompiler.flash.types.CLIPACTIONRECORD;
 import com.jpexs.decompiler.flash.types.CLIPACTIONS;
 import com.jpexs.decompiler.flash.types.CXFORMWITHALPHA;
 import com.jpexs.decompiler.flash.types.ColorTransform;
@@ -388,12 +388,11 @@ public class PlaceObject3Tag extends CharacterIdTag implements Container, PlaceO
      * @return List of sub-items
      */
     @Override
-    public List<ContainerItem> getSubItems() {
-        List<ContainerItem> ret = new ArrayList<>();
+    public List<CLIPACTIONRECORD> getSubItems() {
         if (placeFlagHasClipActions) {
-            ret.addAll(clipActions.clipActionRecords);
+            return clipActions.clipActionRecords;
         }
-        return ret;
+        return new ArrayList<>();
     }
 
     /**
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject4Tag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject4Tag.java
index 752cdbc85..02e109734 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject4Tag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/PlaceObject4Tag.java
@@ -24,9 +24,9 @@ import com.jpexs.decompiler.flash.abc.CopyOutputStream;
 import com.jpexs.decompiler.flash.configuration.Configuration;
 import com.jpexs.decompiler.flash.tags.base.CharacterIdTag;
 import com.jpexs.decompiler.flash.tags.base.Container;
-import com.jpexs.decompiler.flash.tags.base.ContainerItem;
 import com.jpexs.decompiler.flash.tags.base.PlaceObjectTypeTag;
 import com.jpexs.decompiler.flash.types.BasicType;
+import com.jpexs.decompiler.flash.types.CLIPACTIONRECORD;
 import com.jpexs.decompiler.flash.types.CLIPACTIONS;
 import com.jpexs.decompiler.flash.types.CXFORMWITHALPHA;
 import com.jpexs.decompiler.flash.types.ColorTransform;
@@ -391,12 +391,11 @@ public class PlaceObject4Tag extends CharacterIdTag implements Container, PlaceO
      * @return List of sub-items
      */
     @Override
-    public List<ContainerItem> getSubItems() {
-        List<ContainerItem> ret = new ArrayList<>();
+    public List<CLIPACTIONRECORD> getSubItems() {
         if (placeFlagHasClipActions) {
-            ret.addAll(clipActions.clipActionRecords);
+            return clipActions.clipActionRecords;
         }
-        return ret;
+        return new ArrayList<>();
     }
 
     /**
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/SoundStreamHeadTag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/SoundStreamHeadTag.java
index 55d98916b..8668721fd 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/SoundStreamHeadTag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/SoundStreamHeadTag.java
@@ -20,7 +20,6 @@ import com.jpexs.decompiler.flash.SWF;
 import com.jpexs.decompiler.flash.SWFInputStream;
 import com.jpexs.decompiler.flash.SWFOutputStream;
 import com.jpexs.decompiler.flash.tags.base.CharacterIdTag;
-import com.jpexs.decompiler.flash.tags.base.Container;
 import com.jpexs.decompiler.flash.tags.base.ContainerItem;
 import com.jpexs.decompiler.flash.tags.base.SoundStreamHeadTypeTag;
 import com.jpexs.decompiler.flash.types.BasicType;
@@ -189,8 +188,9 @@ public class SoundStreamHeadTag extends CharacterIdTag implements SoundStreamHea
                 head.setVirtualCharacterId(containerId);
                 continue;
             }
-            if (t instanceof Container) {
-                populateSoundStreamBlocks(((CharacterIdTag) t).getCharacterId(), ((Container) t).getSubItems(), head, output);
+            if (t instanceof DefineSpriteTag) {
+                DefineSpriteTag sprite = (DefineSpriteTag) t;
+                populateSoundStreamBlocks(sprite.getCharacterId(), sprite.getSubItems(), head, output);
             }
             if (!found) {
                 continue;
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/base/Container.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/base/Container.java
index 8f1cfa8d0..40a592bc4 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/base/Container.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/base/Container.java
@@ -12,7 +12,8 @@
  * Lesser General Public License for more details.
  * 
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library.
 */
+ * License along with this library.
+ */
 package com.jpexs.decompiler.flash.tags.base;
 
 import com.jpexs.decompiler.flash.treeitems.TreeItem;
@@ -30,7 +31,7 @@ public interface Container extends TreeItem {
      *
      * @return List of sub-items
      */
-    public List<ContainerItem> getSubItems();
+    public List<? extends ContainerItem> getSubItems();
 
     /**
      * Returns number of sub-items
diff --git a/src/com/jpexs/decompiler/flash/gui/tagtree/TagTreeModel.java b/src/com/jpexs/decompiler/flash/gui/tagtree/TagTreeModel.java
index 8aa91cc22..45a171761 100644
--- a/src/com/jpexs/decompiler/flash/gui/tagtree/TagTreeModel.java
+++ b/src/com/jpexs/decompiler/flash/gui/tagtree/TagTreeModel.java
@@ -167,9 +167,10 @@ public class TagTreeModel implements TreeModel {
             frames.add(timeline.getFrames().get(i));
         }
 
-        for (int i = 0; i < sounds.size(); i++) {
-            if (sounds.get(i) instanceof SoundStreamHeadTypeTag) {
-                List<SoundStreamBlockTag> blocks = ((SoundStreamHeadTypeTag) sounds.get(i)).getBlocks();
+        for (int i = sounds.size() - 1; i >=0 ; i--) {
+            TreeItem sound = sounds.get(i);
+            if (sound instanceof SoundStreamHeadTypeTag) {
+                List<SoundStreamBlockTag> blocks = ((SoundStreamHeadTypeTag) sound).getBlocks();
                 if (blocks.isEmpty()) {
                     sounds.remove(i);
                     i--;