Logging on to MCU with an AD user has stopped working since upgrading Control Center to version 4.2.1. Configuring AD in MCU fails when using Control Center 4.2.x (4270962)

Logging on to Management Console for Unix (MCU)  with an Active Directory(AD) user has stopped working since upgrading Control Center to version 4.2.1.

This issue also happens in a new setup scenario when trying to configure Active Directory in MCU. 

The error message shown is:
Communication error. [Error performing LDAP operation]

The following error is also shown in the Management Console for Unix debug output:
Caused by: javax.naming.SizeLimitExceededException: [LDAP: error code 4 - Sizelimit Exceeded]; remaining name 'CN=Schema,CN=Configuration,DC=mylab,DC=com'

Where the CN mentioned is the schema for the domain.


If you try to reinstall MCU you cannot get any further than the Active Directory configuration screen which errors with:
Active Directory verification failed because Error performing LDAP operation

STATUS:
Waiting for a fix in a future release of Management Console for Unix

WORKAROUND:
Add the Starling attributes in Control Center.


For reference the steps are:

- Open the Authentication Services Control Center.

- Scroll to the 'Starling Two-Factor Authentication' section.

- Click on “Starling Attributes” and add the following:
--------------------------------
User Mobile Number:     mobile
User email Address:       mail
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Note that these are the default attributes used by Starling, however the issue occurs when these entries are left blank in Control center.

- Restart the MCU service and try again.