Windows 10: Printer issues after June 2020 Updates

[German]The cumulative security updates released on June 9, 2020 for various versions of Windows 10 are causing serious printing problems for many users. Here is an overview of what I know so far.

I have described the updates for the various versions of Windows 10 and its server counterparts in the blog post Patchday: Windows 10-Updates (June 9, 2020). And the error description in the blog post Windows 10 Bug: USB printers not detected has nothing to do with the printing problems described here.

First user reports about printing issues

After I published the German blog post Patchday: Windows 10-Updates (9. Juni 2020), there were soon numerous reports of printing problems under Windows 10. In this comment German blog reader Ollart writes:

Attention, in our environment the update causes big problems – PDF files are no longer generated. Origin is still unknown.

Up to now only uninstalling the update helps. More information will follow when we know more.

It concerns currently various 1909/2004 Win 10 / server system. KB4560960 or KB4557957.

In a further comment, blog reader Zanza then also confirms that there are powerful printing issues.

After installing the updates, W10 Build 1903 has some printing problems. Various applications simply crash when you try to print. You can always see an appcrash of splwow64.exe in the event log.

This may be related to the PDFs generation problem of Ollat. PDFs are also created by (virtual) printers.

But it should be mentioned that it does not affect every user who has installed the cumulative updates on Windows 10. Blog reader PierreH provides the following information in this comment:

KB4560960 for Win 1909 causes an error message "PrintIsolationHost" Not working (appcrash) on my PCs when printing.
The printer is a Brother configured via WLAN.
If I uninstall the CU it works again with printing. Does someone else have the same problem?

If you search for 'PrintIsolationHost.exe KB4560960' you will find this Microsoft Answers forum post, where a German user has posted a similar error description. Another Microsoft Answers forum post can be found here (it says that Microsoft knows about the error and wants to distribute a patch with the upcoming update, which will probably be July 2020). Also at reddit.com, for example, there is this thread with a similar description – and the colleagues from Bleeping Computer have dug up other sites besides the links above. And Woody Leonhard published summary at Computer World.

Also administrators of Windows Server 2012 systems run into this problem (see Spiceworks entry). There update KB4561612 is the culprit.

PCL5 driver as problem, PCL6 driver works

In the blog post Are Windows 10 update related printing issues are back? reader A.G. MacNeill left me the following feedback:

I just came across this forum as I am searching for a solution to a new- but very similar issue. There is a new update causing more issues.
Cumulative update KB4560960 has rendered a printers using PCL5 useless.
Removing the PCL5 driver and installing a PCL 6 (or postscript if applicable) resolves the problem.

However that's easier said than done, when you're the printer tech supporting hundreds of clients in hundreds of locations!

I've been getting support calls for the last 2 days, and I expect it to increase as more and more people get back to their updated PC's. Anyone seen this, or have a different (more user friendly) workaround, etc??

This thread on reddit.com also provides such an explanation. The PCL5 driver was rendered unusable by the cumulative updates and is causing the problems. An available PCL6 driver solves the problem. Therefore, uninstalling and reinstalling the printer drivers may provide the solution. If necessary, you can also try to see if the Universal Printer driver provides this PCL6 support.

Printers with PostScript output do not seem to be affected by the updates.

Another recommendation is to uninstall the cumulative update from June 2020 to get the printers working again. However, administrators should be aware that the vulnerabilities closed by the update are still open.

Addendum: There are now out-of-band updates released to fix these printer issues from Windows 8.1 up to Windows 10 and it's server pendants. Details may be found within the following two blog posts:

Windows 10: Out-of-band update to fix printer issues – I
Windows 10: Out-of-band update to fix printer issues – II

Similar articles:
Patchday: Windows 10-Updates (June 9, 2020)
Windows 10 Bug: USB printers not detected
Windows 10: SMBleed vulnerability in SMBv3 protocol
Windows 10 Version 2004: External display turns black
Windows 10 version 2004: Graphics issues with multi monitor and f.lux