Remove all resource data from ftex clearing to prevent key issues

Switch_FileFormatsMain/FileFormats/BFRES/BFRESGroup.cs

@@ -396,12 +396,13 @@ namespace Bfres.Structs
 
             if (result == DialogResult.Yes)
             {
-                foreach (var node in Nodes)
+                foreach (TreeNode node in Nodes)
                 {
                     if (node is STGenericWrapper)
                     {
                         ((STGenericWrapper)node).Unload();
                         RemoveChild(((STGenericWrapper)node));
+                        ResourceNodes.Remove(node.Text);
                     }
                 }
                 

Switch_FileFormatsMain/FileFormats/BFRES/Bfres Structs/SubFiles/FTEX.cs

@@ -129,6 +129,12 @@ namespace Bfres.Structs
             return importer;
         }
 
+        public override void Unload()
+        {
+            DisposeRenderable();
+            Nodes.Clear();
+        }
+
         public void ReplaceImage(Image image, string FileName)
         {
             GTXImporterSettings setting = SetImporterSettings(image, FileName);