We have been informed that last week some additional fields were added to GFS model GRIB files, which causes MAIA4 (in AAPP v8.4) to fail.
Meteo-France have provided a fix: I have posted it at ftp://ftp.eumetsat.int/pub/NWPSAF/aapp_data_files/miscellaneous/. So if you use MAIA4, download the maia_Read_GribApi.F90 file to directory AAPP/src/maia4/libmaia4, then go to the AAPP top directory and “make”.
We will add this to the next AAPP update release.
Nigel