Windows 10 KB5001649 out-of-cycle emergency update is rolling
out to enable the mitigation for two critical bugs – blue
screens and printing.

It is the second emergency update released this month and it
has been released to fix issues with Windows 10’s March 2021
updates and the last emergency updates, which were causing
stability problems, BSOD, and, in some cases, weird results
when printing documents.

According to our tests, the Windows KB5001649 update contains
the following fixes:

• Fixes Blue Screen of Death caused by March 2021 update.
• Fixes an issue where the document might print as solid
  black/color boxes.
• Fixes an issue where elements, logo, barcodes, etc would be
  missing on the invoice and other documents.
• Fixes an issue where table lines might be missing.
• Fixes an issue where a printed document will result in a
  blank page. This also affects software-based printing

After we reported that many users had begun experiencing blue
screens and printing problems,
Microsoft issued a statement acknowledging the critical
bug. Microsoft also offered a temporary workaround, but the
workaround couldn’t fix the issue for everyone, and another fix
was issued in the form of an out-of-band cumulative update.

Incredibly,
hotfix also contained printing issues and some folks
reported fresh problems, including a bug where Windows won’t
print documents with all texts, elements, and invoices will
only have the company’s logo.

With today’s update, Microsoft seems to have fixed the blue
screen error code “APC_INDEX_MISMATCH” and several printing
issues in Windows 10 version 1803 and newer.

For those on version 20H2/2004, Microsoft is pushing Windows 10
KB5001649. To download this patch, simply check for updates and
the following update will appear on your screen:

2021-03 Cumulative Update for Windows 10 Version 20H2
for x64-based Systems (KB5001649)

As you can see in the above screenshot, you need to click on
“Download and install” to apply the emergency patch. If you’re
unable to apply the cumulative update via the Settings app,
Microsoft has also published offline installers.

Download links for KB5001649 offline installer

Windows 10 KB5001649 Direct Download Links: 64-bit and
32-bit (x86).

Printing fix for older versions of Windows

In addition to version 20H2 and version 2004, Microsoft has
also issued a second hotfix for older versions of the operating
system. For version 1909, there’s a new patch labelled as
Windows 10 KB5001648 and it includes
identical fixes.

For those using Windows 10 versions from the year 2019 and
2018, there’s a new update available for your device too.

List of March 18 Windows Update updates:

• Windows 10 version 20H2/2004 – KB5001649 (Build 19041.870
  and Build 19042.870)
• Windows 10 version 1909/1903 – KB5001648 (Build 18363.1443)
• Windows 10 version 1809 – KB5001638 (Build 17763.1823)
• Windows 10 version 1803 – KB5001634 (Build 17134.2090)

Microsoft recommends installing the patch only if you’ve blue
screens and printing problems. If you don’t have any such
issues, it’s safe to skip the additional updates and wait for
the April 2021 Patch Tuesday release.

What are the printing issues in the latest update?

Over the weekend, users told us that they cannot print anything
properly after applying the latest updates, which includes the
last hotfix. For some folks, parts of a printed document would
be missing, such as the table or the rows/columns of the table.

For others, documents will print with solid black/colour boxes
and the company’s logo. Of course, there’s another bug
where Windows 10 won’t print anything, even if you use
software-based solutions like “Print to PDF”.

It’s also possible that black pages will be printed or nothing
will happen when using software-based printing.

Important notice: This patch appears to be plagued with
installation issues and it might not install on your device. If
you really need the update, get it using the offline
installers.