One ecu French coin- no yare.

Can you please say from wath yare is this French one ecu silver coin ,l can't see any yare here. Is this a common thing?
The weight of the coin is 30,55 g.
I would appreciate if someone could help.

Did you try to search for “France” and “Precious” metal and 30.55 as weight?

I think though that's it more a medal or jeton than a coin. Does it get attracted to a magnet?

Here is your coin (1715-1718) :-)

N#27853

Weird reverse though, with upper part (date, beginning of legend, part of crown) missing and showing obverse duplicate instead 🤔

This was a period of frequent re-coinage and overstrikes.  Probably the date has been obliterated during the overstrike process.

The coin doesn't attract to magnet .
l looked the description in Numista Catalog , it's the same. If the coin is made by other metal different from the original as you suggested in your post the weight of the coin has to be 1 or 2 gr. lower than usual, but in this case it's  almost the same -30,55 gr. with very small difference from the standard coin.
I agree with the opinions stated in the second post. The reverse is a bit strange . 
I also agree with the last post concerning the coin. 
I also tink tath re-coinage is most probably the reason for the double impression on some parts of the coin. 
But my questions  concerns the absence of the yare in the legend .
I understand that this difference may be random . But can someone say how frequent is this difference, is it common or rare?🤔

penko-to

The coin doesn't attract to magnet .
l looked the description in Numista Catalog , it's the same. If the coin is made by other metal different from the original as you suggested in your post the weight of the coin has to be 1 or 2 gr. lower than usual, but in this case it's  almost the same -30,55 gr. with very small difference from the standard coin.
I agree with the opinions stated in the second post. The reverse is a bit strange . 
I also agree with the last post concerning the coin. 
I also tink tath re-coinage is most probably the reason for the double impression on some parts of the coin. 
But my questions  concerns the absence of the yare in the legend .
I understand that this difference may be random . But can someone say how frequent is this difference, is it common or rare?@

Do you mean year?
As explained above, it should appear at the end of reverse legend, but it is precisely were the strike is deficient and shows something else instead.

Yes l meant the yare .

In my experience, the value of coins which have been struck over and the date has been erased in this process are worth less than coins with a visible date.

Rather than being considered an error, it is considered part of the normal minting process for that time, which has resulted in a less desirable coin (no date).

And welcome to Numista!  You have some very interesting coins.

Tank you very much ! 
The information you have provided is very valuable . It was interesting for me to know if this is a error or not .
I have some other coins for which l would like to hear your opinion and tath of other members of the forum. I will post them very soon.