same problem here! What I know, screenscraper.fr and its API is blocked for non-registered users up to now.
The hint with the recalbox.conf to add user credentials (from registration at screenscraper.fr) helps a lot in order to call the API as registrated user, which I will try. Thanks!
The status update to the API on screenscraper.fr says:
"The API is closed to all anonymous users (not registered for free on ScreenScraper) for now.
The CPU occupancy rate of the main server seems very high."
I think, that their new setup with loadbalancing still does not work, since CPU1 = 84% and CPU2 = 12%... (ideally it should be 50%/50%) but I don't know their internals.