Unable to add a secondary Desktop Delivery Controller (DDC) to an existing site. The following error might be noticed in a CDF trace:

XenDesktop Management Console:1:1: [3] [Error Dialog]
[Content]
An object or column name is missing or empty. For SELECT INTO statements, verify each column has a name. For other statements, look for empty alias names. Aliases defined as "" or [] are not allowed. Change the alias to a valid name.
An object or column name is missing or empty. For SELECT INTO statements, verify each column has a name. For other statements, look for empty alias names. Aliases defined as "" or [] are not allowed. Change the alias to a valid name.
Failed to create database user for [DOMAIN\DDCCOMPUTERACCOUNT$]

Solution 1.

Validate that the correct SID for the account adding the DDC to the site is used. If the behavior still persists, call the Microsoft SQL Support to assist.

Solution 2.
Create a registry to delete cache and delete this Delivery Controller's machine account from database.

Create this registry in all SQL servers hosting the database in the site to disable SID cache.

1.    Open Registry Editor, and then locate the following subkey: 

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa 

2.    Right-click Lsa, click New, and then click DWORD Value. 

3.    Type LsaLookupCacheMaxSize, and then press ENTER to name the new value. 

4.    Right-click LsaLookupCacheMaxSize, and then click Modify. 

5.    In the Value data box, type 0, and then click OK. 

6.    Exit Registry Editor. 

In SQL Server Management Studio, go to Security - Logins and delete the existing Delivery Controller's Machine account.
You should try now to add the Delivery Controller.

Problem Cause

This behavior can be caused due to the SQL database containing a corrupted or mismatched SID for the log on used to add the second DDC.

or 

Existing account that is still in database and SID could already be cached for secondary DDC.