diff --git a/components/ideintf/componenttreeview.pas b/components/ideintf/componenttreeview.pas
index f7585442a3..0a5bf8ebbd 100644
--- a/components/ideintf/componenttreeview.pas
+++ b/components/ideintf/componenttreeview.pas
@@ -748,8 +748,8 @@ begin
         FCollapsedComps := TAVLTree.Create;
         FRoot2CollapasedMap[RootObject] := FCollapsedComps;
       end;
-      RestoreExpand(RootNode);     // then restore the Expanded/Collapsed state.
     end;
+    RestoreExpand(RootNode);     // then restore the Expanded/Collapsed state.
     MakeSelectionVisible;
   end;
   EndUpdate;
diff --git a/ide/checklfmdlg.lfm b/ide/checklfmdlg.lfm
index 3d2e92a126..4317e00b82 100644
--- a/ide/checklfmdlg.lfm
+++ b/ide/checklfmdlg.lfm
@@ -9,7 +9,7 @@ object CheckLFMDialog: TCheckLFMDialog
   ClientWidth = 552
   OnClose = FormClose
   OnCreate = CheckLFMDialogCreate
-  LCLVersion = '1.1'
+  LCLVersion = '2.3.0.0'
   object NoteLabel: TLabel
     Left = 0
     Height = 15
@@ -17,7 +17,6 @@ object CheckLFMDialog: TCheckLFMDialog
     Width = 552
     Align = alTop
     Caption = 'NoteLabel'
-    ParentColor = False
     WordWrap = True
   end
   object LFMGroupBox: TGroupBox
@@ -585,7 +584,6 @@ object CheckLFMDialog: TCheckLFMDialog
       Caption = 'Cancel'
       Kind = bkCancel
       ModalResult = 2
-      NumGlyphs = 0
       TabOrder = 0
     end
     object RemoveAllButton: TBitBtn
@@ -597,7 +595,6 @@ object CheckLFMDialog: TCheckLFMDialog
       AutoSize = True
       BorderSpacing.Around = 6
       Caption = 'Remove all invalid properties'
-      NumGlyphs = 0
       OnClick = RemoveAllButtonClick
       TabOrder = 1
     end
@@ -605,12 +602,6 @@ object CheckLFMDialog: TCheckLFMDialog
   object SynLFMSyn1: TSynLFMSyn
     DefaultFilter = 'Lazarus Form Files (*.lfm)|*.lfm'
     Enabled = False
-    CommentAttri.FrameEdges = sfeAround
-    IdentifierAttri.FrameEdges = sfeAround
-    KeyAttri.FrameEdges = sfeAround
-    NumberAttri.FrameEdges = sfeAround
-    SpaceAttri.FrameEdges = sfeAround
-    StringAttri.FrameEdges = sfeAround
     left = 129
     top = 104
   end
diff --git a/ide/checklfmdlg.pas b/ide/checklfmdlg.pas
index a1168c62ee..5f2c8a801f 100644
--- a/ide/checklfmdlg.pas
+++ b/ide/checklfmdlg.pas
@@ -178,6 +178,8 @@ var
   end;
   
   procedure FindMissingClass(ObjNode: TLFMObjectNode);
+  // Add a missing or nested class to MissingClasses.
+  // A nested class means a TFrame installed as a component.
   var
     i: Integer;
     AClassName: String;
@@ -194,14 +196,16 @@ var
     // search in designer base classes
     if BaseFormEditor1.FindDesignerBaseClassByName(AClassName,true)<>nil then
       exit;
+    // search in global registered classes
+    if GetClass(ObjNode.TypeName)<>nil then
+      exit;
     // search in registered classes
     RegComp:=IDEComponentPalette.FindRegComponent(ObjNode.TypeName);
-    if (RegComp<>nil) and (RegComp.GetUnitName<>'') then exit;
-    // search in global registered classes
-    if GetClass(ObjNode.TypeName) <> nil then
-      Exit;
+    if (RegComp<>nil) and (RegComp.GetUnitName<>'')
+    and not RegComp.ComponentClass.InheritsFrom(TCustomFrame) then // Nested TFrame
+      exit;
     // class is missing
-    DebugLn(['FindMissingClass ',ObjNode.Name,':',ObjNode.TypeName,' IsInherited=',ObjNode.IsInherited]);
+    DebugLn(['QuickCheckLFMBuffer->FindMissingClass ',ObjNode.Name,':',ObjNode.TypeName,' IsInherited=',ObjNode.IsInherited]);
     if MissingClasses=nil then
       MissingClasses:=TStringList.Create;
     MissingClasses.Add(AClassName);
diff --git a/ide/customformeditor.pp b/ide/customformeditor.pp
index d4fc0cb8a5..bf1836ac9b 100644
--- a/ide/customformeditor.pp
+++ b/ide/customformeditor.pp
@@ -2220,12 +2220,13 @@ begin
   or (IndexOfDesignerBaseClass(TComponentClass(AClass))>=0) then begin
     exit;
   end;
-  //DebugLn(['TCustomFormEditor.JITListFindAncestors Class=',DbgSName(AClass)]);
-  AnUnitInfo:=Project1.UnitWithComponentClass(TComponentClass(AClass));
+  DebugLn(['TCustomFormEditor.JITListFindAncestors Class=',DbgSName(AClass)]);
+  AnUnitInfo:=Project1.UnitWithComponentClassName(AClass.ClassName);
+  //AnUnitInfo:=Project1.UnitWithComponentClass(TComponentClass(AClass));
   while AnUnitInfo<>nil do begin
-    {$IFDEF VerboseFormEditor}
+    {.$IFDEF VerboseFormEditor}
     DebugLn(['TCustomFormEditor.JITListFindAncestors FOUND ancestor ',DbgSName(AnUnitInfo.Component),', streaming ...']);
-    {$ENDIF}
+    {.$ENDIF}
     Ancestor:=AnUnitInfo.Component;
     BinStream:=nil;
     if SaveUnitComponentToBinStream(AnUnitInfo,BinStream)<>mrOk then begin
@@ -2254,7 +2255,9 @@ var
 begin
   //DebugLn(['TCustomFormEditor.JITListFindClass ',ComponentClassName]);
   RegComp:=IDEComponentPalette.FindRegComponent(ComponentClassName);
-  if RegComp<>nil then begin
+  if (RegComp<>nil) and
+  not RegComp.ComponentClass.InheritsFrom(TCustomFrame) then // Nested TFrame
+  begin
     //DebugLn(['TCustomFormEditor.JITListFindClass ',ComponentClassName,' is registered as ',DbgSName(RegComp.ComponentClass)]);
     ComponentClass:=RegComp.ComponentClass;
   end else begin
@@ -2264,7 +2267,7 @@ begin
       AnUnitInfo:=TUnitInfo(JITList.ContextObject);
       if AnUnitInfo.ComponentFallbackClasses<>nil then
         for i:=0 to AnUnitInfo.ComponentFallbackClasses.Count-1 do begin
-          if SysUtils.CompareText(AnUnitInfo.ComponentFallbackClasses[i],ComponentClassName)=0
+          if CompareText(AnUnitInfo.ComponentFallbackClasses[i],ComponentClassName)=0
           then begin
             {$IFDEF EnableNestedComponentsWithoutLFM}
             ComponentClass:=TComponentClass(Pointer(AnUnitInfo.ComponentFallbackClasses.Objects[i]));
@@ -2281,7 +2284,7 @@ begin
     AnUnitInfo:=Project1.FirstUnitWithComponent;
     while AnUnitInfo<>nil do begin
       Component:=AnUnitInfo.Component;
-      if SysUtils.CompareText(Component.ClassName,ComponentClassName)=0 then
+      if CompareText(Component.ClassName,ComponentClassName)=0 then
       begin
         DebugLn(['TCustomFormEditor.JITListFindClass found nested class '+DbgSName(Component)+' in unit '+AnUnitInfo.Filename]);
         ComponentClass:=TComponentClass(Component.ClassType);
@@ -2293,8 +2296,7 @@ begin
   //DebugLn(['TCustomFormEditor.JITListFindClass Searched=',ComponentClassName,' Found=',DbgSName(ComponentClass)]);
 end;
 
-function TCustomFormEditor.GetDesignerBaseClasses(Index: integer
-  ): TComponentClass;
+function TCustomFormEditor.GetDesignerBaseClasses(Index: integer): TComponentClass;
 begin
   Result:=TComponentClass(FDesignerBaseClasses[Index]);
 end;
diff --git a/ide/sourcefilemanager.pas b/ide/sourcefilemanager.pas
index 257ecfd1e6..667f775f56 100644
--- a/ide/sourcefilemanager.pas
+++ b/ide/sourcefilemanager.pas
@@ -6602,7 +6602,8 @@ var
     if FoundComponentClass=nil then
     begin
       RegComp:=IDEComponentPalette.FindRegComponent(aClassName);
-      if RegComp<>nil then
+      if (RegComp<>nil) and
+      not RegComp.ComponentClass.InheritsFrom(TCustomFrame) then // Nested TFrame
         FoundComponentClass:=RegComp.ComponentClass;
     end;
     if FoundComponentClass=nil then
@@ -6820,7 +6821,8 @@ var
 
       // search ancestor in registered classes
       if TryRegisteredClasses(AncestorClassName,AncestorClass,TheModalResult) then
-        exit(true);
+        raise Exception.Create('TryFindDeclaration: TryRegisteredClasses returned True!');
+        //exit(true);
 
       {$IFDEF VerboseLFMSearch}
       debugln(['TryFindDeclaration declaration of ',AComponentClassName,' found at ',NewTool.CleanPosToStr(NewNode.StartPos),' Ancestor="',AncestorClassName,'", but no lfm and no registered class found']);
@@ -6868,7 +6870,8 @@ var
     end;
     StoreComponentClassDeclaration(UnitFilename);
     if TryRegisteredClasses(AncestorClassName,AncestorClass,TheModalResult) then
-      exit(true);
+      raise Exception.Create('TryUsedUnitInterface: TryRegisteredClasses returned True!');
+      //exit(true);
   end;
 
 var