Diagnosis
The "Check Paper Size" error on the Canon imageCLASS MF269dw II occurs because of a mismatch between the software-defined page size and the hardware-defined tray setting. This printer utilizes a logic check where the driver (on your PC or Mac) tells the printer to expect a specific size—for example, "Letter"—but the printer's internal sensor or tray configuration is set to something else, such as "A4" or "Custom." Unlike inkjet printers that may simply print the image off-center, the MF269dw II is designed to halt all operations to prevent paper jams or ink/toner waste on the wrong media. This is often triggered when a document is sent as "A4" by a web browser or PDF viewer, while the physical tray is loaded with "Letter" size paper. To confirm this is the issue, look at the printer's LCD screen; it will typically display the specific size it is expecting versus what it thinks is loaded.
How to Fix It
To resolve this, you must synchronize the software settings on your computer with the physical settings on the printer hardware. Follow these exact steps:
- On your Windows computer, open the Control Panel and navigate to Devices and Printers.
- Right-click the Canon MF269dw II icon and select Printing Preferences.
- Navigate to the Page Setup tab. Locate the Page Size dropdown menu. If you are using standard US paper, ensure this is set strictly to Letter (8.5" x 11.0").
- Click the Output Size dropdown directly below Page Size and ensure it is also set to Letter. If these two do not match, the printer will trigger the error.
- Click Apply and then OK.
- Now, go to the physical printer. Press the Menu button on the control panel.
- Navigate to Paper Settings > Paper Selection > Cassette 1.
- Ensure the Paper Size is set to Letter. If it says "Auto" or "A4," manually change it to Letter.
- Press the OK button to save the setting and exit the menu.
If That Didn't Work
- Adjust the Physical Paper Guides: Open the paper cassette and ensure the plastic guides are snug against the edges of the paper stack. If the guides are even 2mm too wide, the printer may detect the paper as a "Custom" size rather than "Letter," triggering the mismatch error. Slide the guides until they click firmly into the Letter-size notches.
- Disable "Auto-Fit" in PDF Settings: If you are printing a PDF from Adobe Acrobat, the "Choose paper source by PDF page size" option is often checked by default. Uncheck this box in the Print dialog window and select "Fit" or "Shrink oversized pages." This prevents the PDF from overriding your driver settings with a non-standard page size.
- Clear the Print Queue: A "stuck" job with the wrong settings can keep the error active even after you fix the settings. Go to your computer's print queue, right-click all pending documents for the MF269dw II, and select Cancel. Restart the printer by unplugging the power cord for 30 seconds to clear the volatile memory.
- Check the Multi-Purpose Tray: If you have paper loaded in the manual feed slot (MP Tray), the printer may be prioritizing that slot over the main cassette. Ensure the MP Tray is completely empty and that the printer is set to pull from "Cassette 1" in the Paper Selection menu.
Heads Up
- Avoid "Auto" Settings: While "Auto" seems convenient, the MF269dw II is prone to misidentifying Letter vs. A4. Manually locking both the driver and the printer to "Letter" is the only way to permanently stop this error.
- Toner Warning: If you frequently change paper sizes, ensure you are using genuine Canon 051 or 051H cartridges; third-party toners can sometimes cause erratic sensor readings during the paper-feed process.
- Firmware Updates: Use the Canon Update utility to check for firmware revisions. Canon released several patches for the imageCLASS series to improve paper size detection logic.
- Paper Quality: Only use 20lb bond paper. Using overly thick cardstock in the main cassette can cause the pickup rollers to slip, which the printer sometimes misinterprets as an incorrect paper size error.