Windows Update - Error Printing

19 August 2020

Microsoft’s latest updates to Windows have been causing some of our customers issues with printing to Print Distributor. These are the general updates that were released on 10th August 2020.

Symptoms

Any print jobs are stuck in the virtual printer with an error state. On versions 5.4 to 6.1 there are no entries in the Print Distributor log. For versions 2017 to 2020 there will be an error message “Ignored empty document on port ###” in the log.

Windows versions affected

Windows 7 through to 10 are all affected as well as Windows Server 2008 R2 and later.

Print Distributor versions 5.4, 6.0 and 6.1 as well as 2017 to 2020 are all affected.

Cause

Print Distributor used a mechanism called Named Pipes to pass print files from a printer port into the Print Distributor service. Named Pipes are a widely used feature of Windows although not commonly used for printer ports. A security vulnerabilty (CVE 2020-1337) was identified in the Windows print spooler and the fix for that appears to have disabled the use of named pipes from printer ports.

Although we moved away from using named pipes from version 2017 they were still supported for systems that were upgraded from previous versions.

Solution

The first stage is to take a backup as some of the following operations can be destructive. You can backup the current Print Distributor configuration using the Tools->Backup menu in Print Distributor. If you get an error about mismatched ports then you can copy the config.xml file which you can find using the Tools->Open Config Folder menu.

For versions 5.4 to 6.1 you will need to upgrade to a newer release. The upgrade is free of charge however you will need to re-enter your license key.

Version 5.4

Version 5.4 can’t be directly upgraded to the current release. Instead you should start by upgrading to 6.1. You can then continue with the instructions for that version.

Versions 6.0 and 6.1

If you are running Windows 7 or Windows Server 2008 R2 then you will need to upgrade to Print Distributor version 2019.12.3. Otherwise you can upgrade to the current release.

Note at this stage you will still have virtual printers using named pipes so the errors will continue. Now follow the instructions for versions 2017 and later.

Versions 2017 to 2020

You will now need to switch each of the virtual printers from the legacy type to the new standard type. To do this delete each virtual printer and create a new one using the Standard printer type. You will then need to add all the actions back in.

Update: Version 2020.08.21

We have just released an update that helps with the conversion of legacy virtual printers to standard. You can now right click on a legacy virtual printer and select the “Convert to standard” menu to convert. The legacy printers are now have a red icon to make them easier to identify.