Update configure-customer-managed-keys.md

Adding new errors about not connecting to the KeyVault

Author: netapp-manishc

articles/azure-netapp-files/configure-customer-managed-keys.md

@@ -445,6 +445,7 @@ This section lists error messages and possible resolutions when Azure NetApp Fil
 | `Volume cannot be encrypted with Microsoft.KeyVault, NetAppAccount has not been configured with KeyVault encryption` | Your NetApp account doesn't have customer-managed key encryption enabled. Configure the NetApp account to use customer-managed key. |
 | `EncryptionKeySource cannot be changed` | No resolution. The `EncryptionKeySource` property of a volume can't be changed. |
 | `Unable to use the configured encryption key, please check if key is active` | Check that: <br> -Are all access policies correct on the key vault: Get, Encrypt, Decrypt? <br> -Does a private endpoint for the key vault exist? <br> -Is there a Virtual Network NAT in the VNet, with the delegated Azure NetApp Files subnet enabled? |
+| `Could not connect to the KeyVault` | Ensure that the private endpoint is set up correctly and the firewalls are not blocking the connection from your Virtual Network to your KeyVault. |
 
 ## Next steps