Issue when saving file in Photoshop

When saving "file as" in Photoshop (latest version) options are greyed/white out in directory as seen on left in photo and Program freezes. Only option to shut down Photoshop in task manager Windows 10 , hi spec PC.

Never happened in previous versions, only happens occasionaly and images I have worked on are sometimes lost, not recoverable despite saving auto every 5 mins . I have reinstalled latest version