Hey heltenjon, sorry to hear that! That issue is new to me, unfortunately I was also unable to replicate a freeze on the save screen there, no matter what I did.
I may have a few ideas as to what could cause that, like something odd with the game trying to find your save directories-
But first if you don't mind my asking, does quick saving (F5) work? Or for that matter saving in any other room, such as the title screen?