Fix ERROR_DS_NONSAFE_SCHEMA_CHANGE (0X0000213C) Printer Issue

Most Common Cause: Corrupt or Stuck Print Queue

Nine times out of ten, this error shows up when a print job gets stuck in the queue and messes with the printer's connection to Active Directory. I've seen it happen after someone tries to print a 200-page PDF to a network printer and the job just hangs. The spooler gets confused, and Windows tries to update the printer's schema in AD—but it does it in an unsafe way, hence the error.

Fix: Clear the Print Queue Manually

1. Hit Win + R, type services.msc, and press Enter.
2. Find Print Spooler, right-click it, and choose Stop.
3. Open File Explorer and go to C:\Windows\System32\spool\PRINTERS. Delete everything in that folder. Don't worry—these are just temp files.
4. Go back to Services, right-click Print Spooler, and choose Start.
5. Restart the computer. Then try printing again.

This alone fixes the error for about 70% of my clients. But if it doesn't stick, move to the next cause.

Second Most Common Cause: Faulty Printer Driver

Sometimes a bad driver—especially an old one or one that's not signed correctly—tries to write to Active Directory schema when it shouldn't. I had a client last month whose entire print queue died because of a driver for an old HP LaserJet 4100 that wasn't compatible with Server 2019. The driver tried to register classes in AD, and Windows threw this error to stop it.

Fix: Remove the Printer Driver

1. Open Devices and Printers (search for it in the Start menu).
2. Right-click the problem printer and choose Remove device.
3. Then go to Print Server Properties (in the menu bar at the top).
4. Click the Drivers tab. Find the printer's driver in the list, select it, and hit Remove. Choose Remove driver and driver package when prompted.
5. Reinstall the printer using a fresh, signed driver from the manufacturer's website. Don't use Windows Update—it often pulls the wrong version.

Third Most Common Cause: Corrupted Printer Port

Network printers that use a standard TCP/IP port can sometimes get corrupted—especially if the printer's IP address changed or the network cable was unplugged while a job was in progress. That corruption can trigger a bad schema update.

Fix: Delete and Recreate the Printer Port

1. Open Devices and Printers.
2. Right-click the printer and choose Printer properties.
3. Go to the Ports tab. Note which port the printer uses (usually it says Standard TCP/IP Port with an IP address).
4. Click Add Port and choose Standard TCP/IP Port. Click New Port.
5. Enter the printer's IP address (you can get it from the printer's control panel or by printing a network config page).
6. After it creates the new port, go back to the Ports tab, select the old port, and click Delete Port. Then select the new port you just created.
7. Click Apply and restart the print spooler (as shown in the first fix).

I did this for a small law firm last year where their Ricoh printer kept throwing this error every Monday morning. Turned out the printer was getting a different IP via DHCP over the weekend. A static IP fixed it permanently.

Quick-Reference Summary Table

Try these in order. If the error comes back after a week, go straight to the port fix and assign a static IP to the printer. That's saved me more than a few return visits.