Microsoft continues fixing printing mess in latest cumulative updates

The recent cumulative updates that Windows 10 received this month, caused disturbance among users with Type 3 printing drivers. Any attempts to print a document on an unpatched system cause BSOD with the APC_INDEX_MISMATCH error code. Microsoft was quick to acknowledge the problem. The company offered a temporary workaround and, after a few days, released two out-of-band patches to address the issue. 

Unfortunately, KB5001567 and KB5001649 went not-so-smooth, and users had hard times installing KB5001649. Instead of adequately applying the patch, Windows was throwing the error message "We couldn't install this update, but you can try again (0x80070541.)" 

Again, after a couple of days, Microsoft halted the rollout and revoked the problematic update. Instead of rolling out KB5001649, the company went back to the previous KB5001567 patch made to fix crashing issues. Now, the update is back and again available on Windows update under optional quality updates. You can go to Windows Settings > Update and Security > Windows Update > Optional quality updates and install the latest patches (KB5001649.) You can also download updates manually from the Windows Update Catalog.  

Our tests and users' reports show that Windows 10 now installs the out-of-band patch with no errors. Hopefully, this time updates fix the problem for good and will not cause any additional issues. 

Be aware that these updates are not mandatory. In fact, Microsoft recommends installing them only if your machine is affected by the printing bug. If your PC prints documents without issues, skip all the optional updates altogether.

According to Microsoft’s investigation, the bug only affects computers with Type 3 printer drivers. Printers with Type 4 drivers are not affected. You can check the driver mode by opening the Print Management and checking the Print Servers > Your PC > Printers section. 

You can learn more about the printing issue in the March cumulative updates in the official Windows 10 Health Dashboard documentation.