When using the Microsoft SQL Server driver this error typically indicates you are using a driver version that is not compatible with the Java version being used in DbVisualizer. Check what Java version is used in Help->About.


First make sure you are using the latest available driver version. 

In DbVisualizer 13.0 and later you can change the driver version and download the new version from Tools->Driver Manger, see new Driver Manger for how to do this.


For older versions of DbVisualizer - click here for download options.


In for example the 7.2.2 driver version these jar files are available:


mssql-jdbc-7.2.2.jre8.jar

mssql-jdbc-7.2.2.jre11.jar


If you are using Java 8 pick the mssql-jdbc-7.2.2.jre8.jar file and for Java 9 and later pick mssql-jdbc-7.2.2.jre11.jar.