HARRISBURG, Pa. (AP) — PennDOT says an error in the hidden security image on Pennsylvania driver’s licenses and identification cards may be causing headaches for some people.

The state Department of Transportation said Thursday that a mistake by its vendors affected an unknown number of cards issued since November.

Officials say new cards were issued starting Thursday and that people whose cards were affected will get new ones in the mail at no cost to them.

The hidden image is a strip of keystones with the letters “PA.” It is clearly visible when held under black light and is used to verify the authenticity of licenses and ID cards. The flawed cards transposed the letters in the image to “AP” instead of “PA.”

PennDOT says the vendors are paying the cost of the replacements.

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