diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/Tag.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/Tag.java
index 7012a5aad..a4009c108 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/Tag.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/tags/Tag.java
@@ -421,6 +421,9 @@ public abstract class Tag implements NeedsCharacters, Exportable, Serializable {
 
     public void undo() throws InterruptedException, IOException {
         byte[] data = getOriginalData();
+        if (data == null) { //If the tag is newly created in GUI it has no original data
+            return;
+        }
         SWFInputStream tagDataStream = new SWFInputStream(swf, data, getDataPos(), data.length);
         readData(tagDataStream, getOriginalRange(), 0, false, true, false);
         setModified(false);
diff --git a/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties b/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties
index c73005244..c38a772fc 100644
--- a/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties
+++ b/src/com/jpexs/decompiler/flash/gui/locales/MainFrame_cs.properties
@@ -602,3 +602,5 @@ tagInfo.neededCharacters = Pot\u0159ebn\u00e9 charaktery
 
 button.viewhexpcode = Zobrazit Hex s instrukcemi
 taginfo.header = Z\u00e1kladn\u00ed informace o tagu
+
+tagInfo.dependentCharacters = Z\u00e1visl\u00e9 charaktery
\ No newline at end of file