Problem: This is a bug introduced in Java 1.8.0_131 and is also in later Java versions. Except for the error window being displayed in DbVisualizer it doesn't seem to have any negative effects when using DbVisualizer.
Solution: DbVisualizer 10.0.7 released on 2018-01-27 includes a fix to prevent the error from being reported in DbVisualizer. The recommendation is to upgrade to this version.
If you are not eligible to use the 10.0.x versions, check your current version in DbVisualizer under Help->About. Then visit the old versions download section in the DbVisualizer web and download the installer that includes Java for that version.