Mint-made error ?

Hello,

I have just bought this JAVA 1812 coin,

is this a strike error? Or a fake?

I would suggest PMD (Post Mint Damage) on a well-used coin.

I say a mint error. Note the clip 180* on the opposite axis (Blakley's Effect in some manner). Check for flow lines around this ill-formed area of the flan. Could be a defective flan type error. Seen these on this coinage more often than not. 

Thanks for your replies!