Cuban Error Coin?

Hello,

I recently got this coin and realized that the denomination is missing on the reverse. It's supposed to be next to the palm tree. Is this an error, and if so, how is it called and how does it happen?

                   Obverse:                                                  Reverse:


Here's how it's supposed to be:
https://en.numista.com/catalogue/pieces928.html

Thanks,
Patrick

I'm not sure about my translation: it would be a(n) obstructed/blocked die, as the die used for minting that coin finally got filled on the numeric 10 inscription.

EDIT: finally it's just an other coin

https://en.numista.com/catalogue/pieces10229.html

Wow, my bad   

Thanks for all the replies. For some reason I didn't find this one when I searched Numista.