In our environment, SQL Server 2012 Servers whenever TLS 1.2 or TLS 1.1 is enabled Application Server is not able to connect to the database.The same issue is observed only on MS SQL Server 2012 related Servers.

Error Message:

Connection failed: SQLState: '01000' SQL Server Error: 1 [Microsoft][ODBC SQL Server Driver][DBNETLIB]ConnectionOpen (SECCreateCredentials()) Connection failed: SQLState: '08001' SQL Server Error: 18 [Microsoft][ODBC SQL Server Driver][DBNETLIB]SSL Security error

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  • Have you installed the update for Windows Server 2012? Most likely, your application server does not support TLS or it has not been set as the default security protocol. Feb 7, 2018 at 6:43
  • @Mr.Brownstone Yes the application supports TLS, and its actually Windows Server 2008R2 (Database Server) and application is on Windows Server 2012. Which side should we apply the update you suggested, application end or database server end, thanks in advance!
    – Sin
    Feb 7, 2018 at 7:13
  • You need to provide a lot more information - like the build numbers of Windows for both the application and the database servers. Also, the build number for SQL Server. Have you taken a look at this article? What have you done to try and resolve it? Feb 7, 2018 at 14:57

1 Answer 1


SQL Server 2012 does not support TLS 1.2 in all SPs or versions. See this table for CU and Hotfix minimum versions https://support.microsoft.com/en-us/help/3135244/tls-1-2-support-for-microsoft-sql-server

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