fixes exception when rendering macros in rte in back office.

src/Umbraco.Web/Macros/PartialViewMacroEngine.cs

@@ -102,6 +102,8 @@ namespace Umbraco.Web.Macros
 
         public string Execute(MacroModel macro, INode node)
         {
+            if (node == null) return string.Empty;
+
             var umbCtx = _getUmbracoContext();
             //NOTE: This is a bit of a nasty hack to check if the INode is actually already based on an IPublishedContent 
             // (will be the case when using LegacyConvertedNode )

src/Umbraco.Web/umbraco.presentation/macro.cs

@@ -23,6 +23,7 @@ using Umbraco.Core.Events;
 using Umbraco.Core.IO;
 using Umbraco.Core.Logging;
 using Umbraco.Core.Macros;
+using Umbraco.Core.Models;
 using Umbraco.Core.Xml.XPath;
 using Umbraco.Core.Profiling;
 using umbraco.interfaces;
@@ -33,7 +34,6 @@ using Umbraco.Web.Models;
 using Umbraco.Web.Templates;
 using umbraco.BusinessLogic;
 using umbraco.cms.businesslogic.macro;
-using umbraco.cms.businesslogic.member;
 using umbraco.DataLayer;
 using umbraco.NodeFactory;
 using umbraco.presentation.templateControls;
@@ -42,6 +42,9 @@ using Content = umbraco.cms.businesslogic.Content;
 using Macro = umbraco.cms.businesslogic.macro.Macro;
 using MacroErrorEventArgs = Umbraco.Core.Events.MacroErrorEventArgs;
 using System.Linq;
+using File = System.IO.File;
+using MacroTypes = umbraco.cms.businesslogic.macro.MacroTypes;
+using Member = umbraco.cms.businesslogic.member.Member;
 
 namespace umbraco
 {
@@ -1849,10 +1852,19 @@ namespace umbraco
         {
             //Get the current content request
 
-            var content = UmbracoContext.Current.PublishedContentRequest != null
+            IPublishedContent content;
+            if (UmbracoContext.Current.IsFrontEndUmbracoRequest)
+            {
+                content = UmbracoContext.Current.PublishedContentRequest != null
                     ? UmbracoContext.Current.PublishedContentRequest.PublishedContent
                     : null;
-        
+            }
+            else
+            {
+                var pageId = UmbracoContext.Current.PageId;
+                content = pageId.HasValue ? UmbracoContext.Current.ContentCache.GetById(pageId.Value) : null;
+            }
+                    
             return content == null ? null : LegacyNodeHelper.ConvertToNode(content);
         }