ERROR Microsoft SQL Server Connector 3:51 Execute failed:


I recently migrated to SQL Server 2019 Developer.
As a host, I tried both the name and
Port 1433

Also both drivers that are available for selection.

  • Original Micrsoft
  • jdts
    With both I get the following error message:

ERROR Microsoft SQL Server Connector 3:51 Execute failed: Fehler beim Herstellen der TCP/IP-Verbindung mit dem Host ‘’, Port 1433. Fehler: ‘Connection refused: connect. Überprüfen Sie die Verbindungseigenschaften. Stellen Sie sicher, dass eine SQL Server-Instanz auf dem Host ausgeführt wird und am Port TCP/IP-Verbindungen akzeptiert. Vergewissern Sie sich, dass am Port keine TCP-Verbindungen durch eine Firewall blockiert werden.’.

ERROR Microsoft SQL Server Connector 3:51 Execute failed: Error establishing the TCP / IP connection with the host ‘’, port 1433. Error: 'Connection refused: connect. Check the connection properties. Make sure that a SQL Server instance is running on the host and accepts TCP / IP connections on the port. Make sure that no firewall is blocking TCP connections on the port. '.

KNIME 4.1.2


How can I fix the problem
Many thanks

Hi there @PatrikS,

you are using Windows native authentication? If so you need to specify it on JDBC Parameters tab for official driver. Check node description or database guide for more info.


Hi Ivan,
thanks for the information. JDBC Parameters tab: integratedSecurity with value true
But that didn’t work.
Tried instance name, localhost and
I also created a new user and tried it with this. Nothing.

Can it be the driver. Mouse over shows me version 7.2.0 of Driver Name.

On the MS website

Microsoft JDBC Driver 8.2.2 for SQL Server

I downloaded the drivers, but I don’t know where to put them.
Here I find only this.

Two weeks ago with SQL Server 2014 everything was still running.


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Hi @PatrikS,

not sure. Will check and come back. Or someone else will.

If you wanna register your own driver check this section guide for steps:


Hi PatrikS,
it is indeed the problem that the driver (version 7.2) is not compatible with SQL Server 2019.
I have created a ticket to update the driver. Until then you can register the driver yourself. Just follow the instruction ipazin has already posted.

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