Qlik Sense - Upgrade failed since it is unable to make a connection to the database server with TLS 1.2

[PadmaPriya]

Environment:

Qlik Sense Enterprise on Windows 

Microsoft SQL Server

Problem 1:

Upgrade of Qlik Sense fails when you try to install Qlik Sense on a computer where:

• The SQL 2012 Native Client is already installed
  And
• The Native Client version is lower than 11.3.6538.0,

The installation fails with the following symptoms:

• When you click Next on the Database Information window, the following message is displayed, even though the information entered is correct.

Unable to make a connection to the database server.

• The Qlik sense setup.log contains the following entries:

SQL::connect to server <SQL server name>
Testing NT Authentication to SQL Server.
Failed to connect to SQL Server [<SQL server name>] with error code [0x80004005]
Description for error code is [TCP Provider: An existing connection was forcibly closed by the remote host.]
Failed in connectToSQLServer with error code [0].
 

Where <SQL_Server_Name> is the name of the SQL Server being used.

Problem 2:

Qlik Sense stops functioning, even after it was successfully installed on a computer, where:

• The SQL 2012 Native Client is already installed, and the version is lower than 11.3.6538.0.
  And
• The Transport Layer Security (TLS) 1.0 is then disabled on the SQL Server.

Cause:

Qlik Sense uses the SQL 2012 Native Client to make connections to SQL. When the client is not present at the time that Qlik Sense is installed, the Qlik Sense installer installs the correct version. But, if an existing version with a lower minor version number is installed, the Qlik Sense installer does not upgrade it.

If the previously installed version only supports TLS 1.0, Qlik Sense is unable to connect to an SQL Server that has TLS 1.0 disabled. This fact can cause the following problems:

• The initial installation of Qlik Sense to fail.
• Qlik Sense stops functioning, if:
• Qlik Sense was installed when TLS 1.0 was enabled on the SQL Server.
  And 
• TLS 1.0 was later disabled. 

Solution:

The solution to both these problems is the same. You must upgrade the SQL 2012 Native Client on the Qlik Sense server to a version that supports TLS 1.2.