diff --git a/src/ce_dialogs.pas b/src/ce_dialogs.pas
index b73a65f6..737eb62b 100644
--- a/src/ce_dialogs.pas
+++ b/src/ce_dialogs.pas
@@ -11,67 +11,80 @@ uses
 (**
  * Ok/Cancel modal dialog
  *)
-function dlgOkCancel(const message: string): TModalResult;
+function dlgOkCancel(const message: string; title: string = ''): TModalResult;
 
 (**
  * Yes/No modal dialog
  *)
-function dlgYesNo(const message: string): TModalResult;
+function dlgYesNo(const message: string; title: string = ''): TModalResult;
 
 (**
  * Info message
  *)
-function dlgOkInfo(const message: string): TModalResult;
+function dlgOkInfo(const message: string; title: string = ''): TModalResult;
 
 (**
  * Error message
  *)
-function dlgOkError(const message: string): TModalResult;
+function dlgOkError(const message: string; title: string = ''): TModalResult;
 
 (**
  * close aFilename Ok/Cancel.
  *)
-function dlgFileChangeClose(const fname: string): TModalResult;
+function dlgFileChangeClose(fname: string; title: string = ''): TModalResult;
 
 const
   DdiagFilter = 'D source|*.d|D interface|*.di|All files|*.*';
+  UnsavedFile = 'Modified file';
+  UnsavedProj = 'Modified project';
+  UnsavedPGrp = 'Modified project group';
 
 implementation
 
 
-function dlgOkCancel(const message: string): TModalResult;
+function dlgOkCancel(const message: string; title: string = ''): TModalResult;
 const
   Btns = [mbOK,mbCancel];
 begin
-  exit( MessageDlg('Coedit', message, mtConfirmation, Btns, ''));
+  if title = '' then
+    title := 'Coedit';
+  exit( MessageDlg(title, message, mtConfirmation, Btns, ''));
 end;
 
-function dlgYesNo(const message: string): TModalResult;
+function dlgYesNo(const message: string; title: string = ''): TModalResult;
 const
   Btns = [mbYes,mbNo];
 begin
-  exit( MessageDlg('Coedit', message, mtConfirmation, Btns, ''));
+  if title = '' then
+    title := 'Coedit';
+  exit( MessageDlg(title, message, mtConfirmation, Btns, ''));
 end;
 
-function dlgOkInfo(const message: string): TModalResult;
+function dlgOkInfo(const message: string; title: string = ''): TModalResult;
 const
   Btns = [mbOK];
 begin
-  exit( MessageDlg('Coedit', message, mtInformation, Btns, ''));
+  if title = '' then
+    title := 'Coedit';
+  exit( MessageDlg(title, message, mtInformation, Btns, ''));
 end;
 
-function dlgOkError(const message: string): TModalResult;
+function dlgOkError(const message: string; title: string = ''): TModalResult;
 const
   Btns = [mbOK];
 begin
-  exit( MessageDlg('Coedit', message, mtError, Btns, ''));
+  if title = '' then
+    title := 'Coedit';
+  exit(MessageDlg(title, message, mtError, Btns, ''));
 end;
 
-function dlgFileChangeClose(const fname: string): TModalResult;
+function dlgFileChangeClose(fname: string; title: string = ''): TModalResult;
 const
   fmt = '"%s" latest modifications are not saved.'#13#10#13#10'Close it without saving ?';
 begin
-  exit(dlgOkCancel(format(fmt, [fname])));
+  if fname = '' then
+      fname := '<not saved yet>';
+  exit(dlgOkCancel(format(fmt, [fname]), title));
 end;
 
 end.
diff --git a/src/ce_editor.pas b/src/ce_editor.pas
index 6a0cbee4..cd40061a 100644
--- a/src/ce_editor.pas
+++ b/src/ce_editor.pas
@@ -489,7 +489,7 @@ begin
   doc := getDocument(index);
   if doc.isNil then exit(false);
   if (doc.modified or (doc.fileName = doc.tempFilename)) and
-    (dlgFileChangeClose(doc.fileName) = mrCancel) then exit(false);
+    (dlgFileChangeClose(doc.fileName, UnsavedFile) = mrCancel) then exit(false);
   doc.disableFileDateCheck:=true;
   pageControl.pageIndex:=index;
   doc.Free;
diff --git a/src/ce_lcldragdrop.pas b/src/ce_lcldragdrop.pas
index 5545566c..624f0a12 100644
--- a/src/ce_lcldragdrop.pas
+++ b/src/ce_lcldragdrop.pas
@@ -137,7 +137,7 @@ begin
   begin
     if assigned(fFreeProj) then
     begin
-      if fFreeProj.modified and (dlgFileChangeClose(fFreeProj.filename) = mrCancel) then
+      if fFreeProj.modified and (dlgFileChangeClose(fFreeProj.filename, UnsavedProj) = mrCancel) then
         exit;
       fFreeProj.getProject.Free;
     end;
diff --git a/src/ce_libman.pas b/src/ce_libman.pas
index 68661a47..c875b784 100644
--- a/src/ce_libman.pas
+++ b/src/ce_libman.pas
@@ -62,7 +62,7 @@ type
     property libFile: string read fLibFile write setLibFile;
     property libProject: string read fLibProject write setLibProject;
     property enabled: boolean read fEnabled write fEnabled default true;
-    // TODO-cmaintenace: remove this property from 3 update 1
+    // TODO-cmaintenance: remove this property from 3 update 1
     property projectFile: string read fLibProject write fLibProject stored false;
   public
     constructor Create(ACollection: TCollection); override;
diff --git a/src/ce_libmaneditor.pas b/src/ce_libmaneditor.pas
index ebae5297..53233f13 100644
--- a/src/ce_libmaneditor.pas
+++ b/src/ce_libmaneditor.pas
@@ -569,7 +569,7 @@ begin
   begin
     if assigned(fFreeProj) then
     begin
-      if fFreeProj.modified and (dlgFileChangeClose(fFreeProj.filename) = mrCancel) then
+      if fFreeProj.modified and (dlgFileChangeClose(fFreeProj.filename, UnsavedProj) = mrCancel) then
         exit;
       fFreeProj.getProject.Free;
     end;
diff --git a/src/ce_main.pas b/src/ce_main.pas
index 531c9a39..9c1d00c9 100644
--- a/src/ce_main.pas
+++ b/src/ce_main.pas
@@ -313,6 +313,7 @@ type
     fMsgs: ICEMessagesDisplay;
     fMainMenuSubj: TCEMainMenuSubject;
     fAppliOpts: TCEApplicationOptions;
+    fProjActionsLock: boolean;
     procedure updateMainMenuProviders;
     procedure updateFloatingWidgetOnTop(onTop: boolean);
 
@@ -380,8 +381,9 @@ type
     procedure saveProj;
     procedure saveProjAs(const aFilename: string);
     procedure openProj(const aFilename: string);
-    procedure closeProj;
+    function closeProj: boolean;
     procedure showProjTitle;
+    function  checkProjectLock(message: boolean = true): boolean;
 
     // mru
     procedure mruChange(Sender: TObject);
@@ -1459,7 +1461,7 @@ begin
   if (fFreeProj <> nil) then
   begin
     if fFreeProj.modified and
-      (dlgFileChangeClose(fFreeProj.filename) = mrCancel) then
+      (dlgFileChangeClose(fFreeProj.filename, UnsavedProj) = mrCancel) then
         exit;
     fFreeProj.getProject.Free;
     fFreeProj := nil;
@@ -1467,7 +1469,7 @@ begin
   for i := fMultidoc.documentCount-1 downto 0 do
     if not fMultidoc.closeDocument(i) then exit;
   if fProjectGroup.groupModified then if
-    (dlgFileChangeClose(fProjectGroup.groupFilename) = mrCancel) then exit;
+    (dlgFileChangeClose(fProjectGroup.groupFilename, UnsavedPGrp) = mrCancel) then exit;
   canClose := true;
   fProjectGroup.closeGroup;
 end;
@@ -1479,7 +1481,7 @@ end;
 
 procedure TCEMainForm.updateProjectBasedAction(sender: TObject);
 begin
-  TAction(sender).Enabled := fProject <> nil;
+  TAction(sender).Enabled := (fProject <> nil) {and not fProjActionsLock};
 end;
 
 procedure TCEMainForm.updateDocEditBasedAction(sender: TObject);
@@ -1660,6 +1662,7 @@ end;
 
 procedure TCEMainForm.projCompiling(aProject: ICECommonProject);
 begin
+  fProjActionsLock := true;
 end;
 
 procedure TCEMainForm.projCompiled(aProject: ICECommonProject; success: boolean);
@@ -1668,6 +1671,7 @@ var
   runprev: boolean = true;
   i: integer;
 begin
+  fProjActionsLock := false;
   if not fIsCompilingGroup then
   begin
     if fRunProjAfterCompile and assigned(fProject) then
@@ -2807,6 +2811,18 @@ end;
 {$ENDREGION}
 
 {$REGION project ---------------------------------------------------------------}
+function  TCEMainForm.checkProjectLock(message: boolean = true): boolean;
+begin
+  result := false;
+  if fProjActionsLock then
+  begin
+    result := true;
+    if message then
+      dlgOkInfo('This action is disabled while a project compiles',
+        'Project lock warning');
+  end
+end;
+
 procedure TCEMainForm.showProjTitle;
 begin
   if (fProject <> nil) and fProject.filename.fileExists then
@@ -2821,6 +2837,7 @@ var
 begin
   if fProject = nil then exit;
   if fProject.filename <> aEditor.fileName then exit;
+  if checkProjectLock then exit;
   //
   fname := fProject.filename;
   fProject.getProject.Free;
@@ -2828,12 +2845,15 @@ begin
   openProj(fname);
 end;
 
-procedure TCEMainForm.closeProj;
+function TCEMainForm.closeProj: boolean;
 begin
+  result := true;
   if fProject = nil then exit;
+  result := false;
   //
   if fProject = fFreeProj then
   begin
+    if checkProjectLock then exit;
     fProject.getProject.Free;
     fFreeProj := nil;
   end;
@@ -2841,14 +2861,16 @@ begin
   fNativeProject := nil;
   fDubProject := nil;
   showProjTitle;
+  result := true;
 end;
 
 procedure TCEMainForm.actProjNewDubJsonExecute(Sender: TObject);
 begin
   if (fProject <> nil) and not fProject.inGroup
     and fProject.modified and
-      (dlgFileChangeClose(fProject.filename) = mrCancel) then exit;
-  closeProj;
+      (dlgFileChangeClose(fProject.filename, UnsavedProj) = mrCancel) then exit;
+  if not closeProj then
+    exit;
   newDubProj;
 end;
 
@@ -2856,8 +2878,9 @@ procedure TCEMainForm.actProjNewNativeExecute(Sender: TObject);
 begin
   if (fProject <> nil) and not fProject.inGroup
     and fProject.modified and
-      (dlgFileChangeClose(fProject.filename) = mrCancel) then exit;
-  closeProj;
+      (dlgFileChangeClose(fProject.filename, UnsavedProj) = mrCancel) then exit;
+  if not closeProj then
+    exit;
   newNativeProj;
 end;
 
@@ -2892,7 +2915,8 @@ end;
 
 procedure TCEMainForm.openProj(const aFilename: string);
 begin
-  closeProj;
+  if not closeProj then
+    exit;
   if aFilename.extractFileExt.upperCase = '.JSON' then
     newDubProj
   else
@@ -2904,21 +2928,25 @@ end;
 
 procedure TCEMainForm.mruProjItemClick(Sender: TObject);
 begin
+  if checkProjectLock then
+    exit;
   if (fProject <> nil) and not fProject.inGroup and
       fProject.modified and
-        (dlgFileChangeClose(fProject.filename) = mrCancel) then exit;
+        (dlgFileChangeClose(fProject.filename, UnsavedProj) = mrCancel) then exit;
   openProj(TMenuItem(Sender).Hint);
 end;
 
 procedure TCEMainForm.actProjCloseExecute(Sender: TObject);
 begin
   if (fProject <> nil) and not fProject.inGroup and fProject.modified and
-    (dlgFileChangeClose(fProject.filename) = mrCancel) then exit;
+    (dlgFileChangeClose(fProject.filename, UnsavedProj) = mrCancel) then exit;
   closeProj;
 end;
 
 procedure TCEMainForm.actProjSaveAsExecute(Sender: TObject);
 begin
+  if checkProjectLock then
+    exit;
   with TSaveDialog.Create(nil) do
   try
     if execute then saveProjAs(filename);
@@ -2930,14 +2958,18 @@ end;
 procedure TCEMainForm.actProjSaveExecute(Sender: TObject);
 begin
   if fProject = nil then exit;
+  if checkProjectLock then
+    exit;
   if fProject.filename.isNotEmpty then saveProj
   else actProjSaveAs.Execute;
 end;
 
 procedure TCEMainForm.actProjOpenExecute(Sender: TObject);
 begin
+  if checkProjectLock then
+      exit;
   if (fProject <> nil) and fProject.modified and
-    (dlgFileChangeClose(fProject.filename) = mrCancel) then exit;
+    (dlgFileChangeClose(fProject.filename, UnsavedProj) = mrCancel) then exit;
   with TOpenDialog.Create(nil) do
   try
     if execute then openProj(filename);
@@ -2978,14 +3010,14 @@ end;
 procedure TCEMainForm.actProjOptViewExecute(Sender: TObject);
 begin
   if fProject = nil then exit;
-  dlgOkInfo(fProject.getCommandLine);
+  dlgOkInfo(fProject.getCommandLine, 'Compilation command line');
 end;
 
 procedure TCEMainForm.actProjOpenGroupExecute(Sender: TObject);
 begin
   if fProjectGroup.groupModified then
   begin
-    if dlgFileChangeClose(fProjectGroup.groupFilename) = mrCancel then
+    if dlgFileChangeClose(fProjectGroup.groupFilename, UnsavedPGrp) = mrCancel then
       exit;
   end;
   fProjectGroup.closeGroup;
@@ -3027,7 +3059,7 @@ procedure TCEMainForm.actNewGroupExecute(Sender: TObject);
 begin
   if fProjectGroup.groupModified then
   begin
-    if dlgFileChangeClose(fProjectGroup.groupFilename) = mrCancel then
+    if dlgFileChangeClose(fProjectGroup.groupFilename, UnsavedPGrp) = mrCancel then
       exit;
   end;
   fProjectGroup.closeGroup;
@@ -3043,10 +3075,17 @@ begin
   fFreeProj := nil;
 end;
 
+// TODO-cFIleOpenDialog: allow multi selection when possible
+//(open file, add file to project, ...)
+
+// TODO-cprojectgroup: handle invalid projects filename when reloading a group
+
 procedure TCEMainForm.actProjGroupCompileExecute(Sender: TObject);
 var
   i: integer;
 begin
+  if checkProjectLock then
+    exit;
   if fProjectGroup.projectCount = 0 then
     exit;
   fGroupCompilationCnt := 0;
@@ -3064,7 +3103,7 @@ procedure TCEMainForm.actProjNewGroupExecute(Sender: TObject);
 begin
   if fProjectGroup.groupModified then
   begin
-    if dlgFileChangeClose(fProjectGroup.groupFilename) = mrCancel then
+    if dlgFileChangeClose(fProjectGroup.groupFilename, UnsavedPGrp) = mrCancel then
       exit;
   end;
   fProjectGroup.closeGroup;
diff --git a/src/ce_miniexplorer.pas b/src/ce_miniexplorer.pas
index ef2f6c1c..523e5b57 100644
--- a/src/ce_miniexplorer.pas
+++ b/src/ce_miniexplorer.pas
@@ -486,7 +486,7 @@ begin
   begin
     if assigned(fFreeProj) then
     begin
-      if fFreeProj.modified and (dlgFileChangeClose(fFreeProj.filename) = mrCancel) then
+      if fFreeProj.modified and (dlgFileChangeClose(fFreeProj.filename, UnsavedProj) = mrCancel) then
         exit;
       fFreeProj.getProject.Free;
     end;
diff --git a/src/ce_synmemo.pas b/src/ce_synmemo.pas
index 397c6dc3..30df4ec5 100644
--- a/src/ce_synmemo.pas
+++ b/src/ce_synmemo.pas
@@ -1175,6 +1175,10 @@ begin
 end;
 
 procedure TCESynMemo.ShowPhobosDoc;
+  procedure errorMessage;
+  begin
+    dlgOkError('html documentation cannot be found for "' + Identifier + '"');
+  end;
 var
   str: string;
   pth: string;
@@ -1190,7 +1194,7 @@ begin
   DcdWrapper.getDeclFromCursor(str, pos);
   if not str.fileExists then
   begin
-    dlgOkInfo('html documentation cannot be found for "' + Identifier + '"');
+    errorMessage;
     exit;
   end;
   // verify that the decl is in phobos
@@ -1199,7 +1203,7 @@ begin
   begin
     if pth.extractFilePath = pth then
     begin
-      dlgOkInfo('html documentation cannot be found for "' + Identifier + '"');
+      errorMessage;
       exit;
     end;
     pth := pth.extractFilePath;