Unable to Print after Applying Windows Update KB5004945 (aka "Print Nightmare" Fix) Follow


BarTender Content Team


After applying the June/July 2021 Windows Security Updates (KB5004945), you may see one or both of the following symptoms:

  • When attempting to print from any application in the BarTender Suite, printer queues get stuck or print jobs get lost even though there is nothing physically wrong with the printer. Restarting the computer or the Print Spooler service does not fix this problem.
  • When printing from BarTender Print Portal, the print job will fail with a message claiming there is a problem with the page setup. If you open the label and look at the page setup dialog, there are no errors.


  • Any version or revision of BarTender
  • Windows 10, version 21H1; Windows 10, version 20H2; Windows 10, version 2004
  • Windows Server, version 20H2; Windows Server, version 2004
  • After installing KB5003690 or later updates (including out of band updates, KB5004760 and KB5004945)
  • Various printers. Most commonly affected are label and receipt printers connected via USB.


Print Nightmare, sometimes called Chaos Print Nightmare, is the nickname for a vulnerability that allowed attackers to remotely execute code using the Print Spooler service. You can read more about the specifics on Microsoft's website here.

KB5004945 was intended to fix the issue, but it had an unintended side effect of stopping printing on various printers, commonly USB label and receipt printers which are often used with BarTender. In response to the issue, Microsoft has now released and pushed a Windows update (KB5004237) that fully addresses the issue.

Additional Information

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