This is a bug introduced in Java 1.8.0_161 and is also in later Java versions.  

Solution: Download and install a DbVisualizer installer that includes a Java version that does not have this problem.

Check your current version in DbVisualizer under Help->About. If you are using version 10.0.x, visit the current version download section, or the old versions download section if you use an older version, in the DbVisualizer web and download the installer that includes Java for that version.