This can happen if licensing agreements with the artist/labels, or ownership of rights, has changed. Availability can vary between countries as well.
Unfortunately, this is something that Spotify doesn't have control over as it is up to the individual music companies and artists.
Hopefully the album you're looking for will reappear soon!
Hey there @yesilyenidunya,
Thanks for posting about this here in the Community!
Hope this helps clarify things! If there's anything else we can help with, don't hesitate to give us a shout.
Have a lovely day 🙂