Cumulative Update 21 includes all application and platform hotfixes and regulatory features that have been released for Microsoft Dynamics NAV 2015.
Note: You must convert the database if you are upgrading to this cumulative update from a cumulative update earlier than Cumulative Update 9 (build 41779). For more information, see Converting a Database in Help for Microsoft Dynamics NAV.
Where to find Cumulative Update 21
You can download the cumulative update from KB 3172546 – Cumulative Update 21 for Microsoft Dynamics NAV 2015 (Build 46293).
Before you install a cumulative update in a production environment, take the following precautions:
- Test the cumulative update in a non-production environment.
- Make a backup of the system or computer where the cumulative update is to be installed.
For information about how to install the cumulative update, see How to Install a Microsoft Dynamics NAV 2015 Cumulative Update.
For information about how to work around a recent process change, see How to Get Back the ‘Hotfix Directories’ from NAV 2015 Cumulative Update 1.
For a list of all cumulative updates for this version, see Released Cumulative Updates for Microsoft Dynamics NAV 2015.
For more details See this Link : https://blogs.msdn.microsoft.com/nav/2016/07/05/cumulative-update-21-for-microsoft-dynamics-nav-2015-has-been-released/