Mint error Nikel 2015 PCGSAn expert on wrong coins in Europe, Stefan Proynov, claims that more and more wrong coins are finding their place on the market.
Here is one registered by PCGS.

For many years, wrong coins were not raised with their rarity, but more and more they are taking their place, says Stefan Proynov.
There is no month in which the leading numismatic companies do not publish one of these and introduce the public to these unique coins.
Here is the PCGS proposal

Wrong 2015 Nickel Coin. certified by PCGS
When a coin is struck, it should be produced from dies that are clean and free of any residue, debris, or other random objects. If, however, there is something between the dies or on the dies or planchet, the result will be a “struck-through” error, resulting in part or even all of the design missing on the coin. For example, this 2015 Nickel is identified as “Struck Through a Piece of Webbing.”

Stefan Proynov: Error coin expert for Europe – I couldn’t miss this unique coin

Source: Mint Error News