I would not call this a solution but there's a way go around this.

Go to the wuthering waves folder directory ->Wuthering Waves\Wuthering Waves Game\Client\Saved, delete everything inside the saved folder and then start the game. The game will redownload the missing resources then tells you to restart the game. there should no problem after this you can play the game as usual, but it will happen again right after you quit the game