This is a result of the MICR reader being unable to translate the MICR line from the bottom of the check.

Terminal Response	Probable Cause	Action Taken
Can't Read Check	Check is being inserted incorrectly.	Ensure the check is being inserted correctly.
	Check is folded or damaged.	Ensure the check being inserted is not wrinkled, torn, wet, creased, or otherwise damaged.
	Check is not printed with MICR ink.	Vanity or Novelty checks (those ordered through aftermarket sources), as well as those printed by smaller local banks and credit unions, are often not printed with MICR ink, therefore are unable to be read by the reader.
	Reader is being effected by EMI.	EMI (Electro-Magnetic Interference) is emitted by any electrical device, ensure that the reader is not too close to any type of electrical equipment that could induce a magnetic field on the MICR reader, keeping it from being able to function.
	Reader is dirty.	Using the cleaning kit that was supplied with the terminal, clean the MICR reader. If the cleaning kit is not available - a can of compressed air can be used to blow any dust or debris out of the MICR reader, also a crisp dollar bill can be used. Run the dollar bill through instead of a check from the insert check prompt several times to remove any dust or debris from the reader.
	Reader is not configured.	Configure MICR reader with the appropriate configuration check.
	Reader is defective.	Have the terminal serviced.