Internationalization problem?

Hi guys,

I have translated Foobox Free in French using GlotPress but my translations don’t work.

As a matter of fact, I have tried many ways (inside /wp-content/languages/, inside /wp-content/plugins/) but none of them seem to work.
I have changed the name of my translations (fooboxfree, foobox-free, foobox-image-lightbox), still nothing.

Could you take a look at this?
Cheers,

– Nicolas

https://ww.wp.xz.cn/plugins/foobox-image-lightbox/