This message is displayed when the Lens Calibration Sheet can not be detected.

Check the following points or solutions

Make sure that the specified lens calibration sheet included with the product is used for calibrating.

If you lose the lens calibration sheet or the sheet is dirty or folded, print a new copy of the sheet.

You can download the lens calibration sheet from this site
Print the sheet in actual size on a plain white paper with your printer.
Make sure that the paper is not dirty, warped, wrinkled or folded before printing.

Click your desired sheet below.

To download the Letter size sheet.

To download the A4 size sheet.

Perform Lens Calibration in a lighted environment.