Earlier today, we reported that a technical issue was preventing access to the ERA5 hourly data on single level and the ERA5 hourly on pressure levels data from the CDS from both the online data download form and the API (and toolbox!).
We are pleased to announce that the issue has been fixed and access to both datasets has been restored (download form/API/toolbox):
We apologise for the inconvenience this may have caused.
C3S Helpdesk at ECMWF