I am getting confused. This netcdf file: http://data.nodc.noaa.gov/thredds/fileServer/ndbc/cmanwx/2011/01/NDBC_WPOW1_201101_D1_v00.nc does not use groups at all. Can you go over in detail the steps you did that led to the error? =Dennis Heimbigner Unidata Ticket Details =================== Ticket ID: SBZ-133456 Department: Support netCDF Java Priority: Critical Status: Closed