[This article is relevant only if you print directly to a printer. If you print a Pdf file instead, this article is not relevant.]

A.  Background

If your labels have suddenly stopped printing and you have not changed anything, the culprit is Java! Either your Java suddenly dislikes your Browser, or your Browser suddenly dislikes your Java, or both.  This is happening more and more these days due to clashes between Java (which has certain vulnerabilities) and your browser (which is trying to over-zealously protect itself from those vulnerabilities).  Java can update automatically without you knowing it, and so can your Browser - which is what causes this issue to occur suddenly and out of the blue.

B.  How to resolve it

  1. From the Windows Control Panel, open Java. Click the "General" tab, and click "Settings". Click "Delete files", and in the popup window, check all the 3 boxes and click 'Ok'. Click 'Ok' again.
  2. In Windows, via Control Panel, uninstall all Java Programs using the standard method for uninstalling software.
  3. Install the latest Java version (currently Java 7 update 13) from here: www.java.com 
  4. From the Windows Control Panel, open Java. In the "Update" tab, un-check the box for "Check for updates automatically" (if a popup comes up, click "Do not check"). Click 'Apply'. Then in the 'Advanced' tab, under Java Plug-in, check the box for "Mozilla family" and also check the box for "Enable the next-generation Java Plugin...". Again, click 'Apply'.
  5. If you are on Windows XP, make sure you have Microsoft's Service Pack 3 (SP3) installed. You probably do, but check anyway.
  6. Reboot your PC.
  7. In Chrome, open a new browser window and type chrome://plugins/   Then hit the Enter key, and scroll down until you see Java. Make sure the the "Always allowed" box is checked. 
  8. In Chrome, open another browser window and type chrome://settings/   Then hit the Enter key, scroll down, and click the link, "Show advanced settings...". Then click the button, "Clear Browsing data...".  In the ensuing dialog box, select "Obliterate the following items from: The beginning of time".  Check the boxes for "Empty the cache" and "Delete cookies and other site and plug-in data". Then click the button, "Clear browsing data".

That should do it!