Fixed bug with several requests of undo in a row.

word/Editor/Document.js

@@ -8366,7 +8366,7 @@ CDocument.prototype.Document_Undo = function(Options)
 
 	if (true !== this.History.Can_Undo() && this.Api && this.CollaborativeEditing && true === this.CollaborativeEditing.Is_Fast() && true !== this.CollaborativeEditing.Is_SingleUser())
 	{
-		if (this.CollaborativeEditing.CanUndo())
+		if (this.CollaborativeEditing.CanUndo() && true === this.Api.canSave)
 		{
 			this.CollaborativeEditing.Set_GlobalLock(true);
 			this.Api.asc_Save(true, true);