After just over three years since it was first released, Qt 5.6 LTS Support has finally come to an end. This means that the version will no longer receive patch level releases, bug and security fixes.
Support has been dropped in favor of Qt 5.9 LTS and related patch level releases. In spite of this, it is better advised to upgrade to the latest Qt 5.12 LTS patch level release.
For those who cannot upgrade for any reason can still sign up for extended support at an additional cost for both Standard as well as Premium Support.