Added workaround for install error on 2017 and below

Author: rajeshsetlem

articles/azure-sql/virtual-machines/windows/failover-cluster-instance-azure-shared-disks-manually-configure.md

@@ -148,6 +148,17 @@ After you've configured the failover cluster and all cluster components, includi
 
 1. In **Failover Cluster Manager**, make sure that all core cluster resources are on the first virtual machine. If necessary, move the disks to that virtual machine.
 
+1. If the version of operating system is Windows Server 2019 and windows cluster was created using the default [**Distributed Network Name (DNN)**](https://blogs.windows.com/windows-insider/2018/08/14/announcing-windows-server-2019-insider-preview-build-17733/), then FCI installation for SQL Server 2017 and below will fail with following error:
+
+    **The given key was not present in the dictionary**
+
+    SQL Server FCI installation queries for existing Virtual Network Name (VNN) and doesn't recognize the Windows Cluster DNN. The issue has been fixed in SQL Server 2019 setup. For SQL Server 2017 and below, follow these steps to avoid FCI installation error:
+     
+    - In Failover Cluster Manager, connect to the cluster, right click  **Roles** and select **Create Empty Role**
+    - Right click the newly created empty role, select **Add Resource** and select **Client Access Point**
+    - Enter any name and complete the wizard to create **Client Access Point**
+    - Upon completion of SQL Server FCI installation, this role which contains just the temporary **Client Access Point** can be deleted. 
+
 1. Locate the installation media. If the virtual machine uses one of the Azure Marketplace images, the media is located at `C:\SQLServer_<version number>_Full`. 
 
 1. Select **Setup**.