There are times when QZTray loses the certificate necessary to load the application for printing directly to printers. If this happens, please follow these steps.
1. Ensure you are running the latest version of Chrome
2. Remove installed QZTray certificates
a. click on QZTray in the system tray and select Site Manager
b. Click on Allowed and Delete the certificate installed.
Close and restart Chrome and then VisualDLP. Then open User Settings and set your Printers.