"Failed to setup database rtcxds" error when you upgrade the SQL Server 2008 R2 back-end database in Skype for Business Server 2015

In a Microsoft Skype for Business Server 2015 environment, you use Microsoft SQL Server 2008 R2 as a back-end database. After you install the July 2018 cumulative update 6.0.9319.534 (CU7) for Skype for Business Server 2015, you may find the SQL Server database can't be upgraded. In addition, you may receive an error message that resembles the following:

This issue occurs because a value of targetRecoveryTime attribute isn't set correctly, and it isn't present in SQL Server 2008 R2.

To fix this issue, install the January 2019 cumulative update 6.0.9319.537 for Skype for Business Server 2015, Core Components.

If you are using SQL Server 2008 R2 as a back-end database but you are not able to update to January 2019 cumulative update 6.0.9319.537 (CU8) immediately, you should also not apply July 2018 Cumulative Update 6.0.9319.534 (CU7). To obtain a guidance for deploying a particular fix together with CU7, please submit a request to Microsoft Customer Service and Support through the following Microsoft website:

http://support.microsoft.com/contactus/?ws=support