When I enter open.spotify.com (or play.spotify.com, which redirects me to "open"), there is no web player displayed. Instead of it, there are some tiles and "Show on Spotify" or "Play on Spotify" messages leading to open the desktop app (which I don't even have installed).
This bug appears on Vivaldi and Chrome, Firefox works OK. Everything worked fine yesterday.
It's a Linux desktop computer. I'm using Spotify Premium -- although I don't know why since I can't play anything :-).
The screenshot contains the screen which appears instead of the player (says "Display on Spotify and "Discover new playlists for every mood and occasion").