Licencing has been updated in 19.0 SP4. These are the changes that have been implemented:

• Modeling tools and plugins are no longer updated automatically. Only the manual update from Service Pack (SP) and major versions to 19.0 SP4 is available. Additionally, the Check for Updates button is removed from the Help menu. Learn more about updating modeling tools and plugins >>
• Resource/Plugin Manager (Help > Resource/Plugin Manager) is updated. The Refresh, Download/Install, and Remove buttons are disabled. Only the manual plugins installation is available. Learn more about installing plugins >>