Issue patching SQL Server 2016 to SP2 CU 15 Trying to update all our SQL 2016 servers to SP2 CU 15, but am running into:
The version of SQL Server instance MSSQLSERVER does not match the version expected 
by the SQL Server update. The installed SQL Server product version is 13.1.4001.0, 
and the expected SQL Server version is 13.2.5026.0.

SSMS shows the server to be at 13.0.4259.0
@@Version shows:
Microsoft SQL Server 2016 (SP1-GDR) (KB4505219) - 13.0.4259.0 (X64)   Jun 15 2019 19:20:12
   Copyright (c) Microsoft Corporation  Standard Edition (64-bit) on Windows Server 2016 
   Datacenter 6.3 &lt;X64&gt; (Build 14393: ) (Hypervisor)

What do I need to do to get the SP2 CU 15 patch applied to this server?
Thanks to SqlWorldWide:

You will need to install SP2 first in order to apply any CU that was released after SP2.

Applying the base SP2 patch allowed me to then apply the CU 15 patch.
Being forced into the DBA role, I tried this CU on our test server which was at the same patch level and CU 15 worked fine, hence my confusion.