U4-11021 No login form when trying to authorise 7.9 upgrade

src/Umbraco.Web/Editors/BackOfficeServerVariables.cs

@@ -376,9 +376,6 @@ namespace Umbraco.Web.Editors
         /// <returns></returns>
         private Dictionary<string, object> GetApplicationState()
         {
-            if (_applicationContext.IsConfigured == false)
-                return null;
-
             var app = new Dictionary<string, object>
             {
                 {"assemblyVersion", UmbracoVersion.AssemblyVersion}
@@ -386,7 +383,9 @@ namespace Umbraco.Web.Editors
 
             var version = UmbracoVersion.GetSemanticVersion().ToSemanticString();
 
-            app.Add("cacheBuster", string.Format("{0}.{1}", version, ClientDependencySettings.Instance.Version).GenerateHash());
+            //the value is the hash of the version, cdf version and the configured state
+            app.Add("cacheBuster", $"{version}.{_applicationContext.IsConfigured}.{ClientDependencySettings.Instance.Version}".GenerateHash());
+
             app.Add("version", version);
 
             //useful for dealing with virtual paths on the client side when hosted in virtual directories especially
@@ -405,4 +404,4 @@ namespace Umbraco.Web.Editors
             return section.MaxRequestLength.ToString();
         }
     }
-}
+}