Earlier today we reported that there were technical issues affecting access to the CMIP5 and CMIP6 data. CORDEX was also affected by this issue.
We are pleased to announce that the issue has been fixed and full access to CMIP5, CMIP6 and CORDEX data from the Climate Data Store (CDS) has been restored.
Apologies for the inconvenience this may have caused.
ECMWF Support