HDF5-DIAG: Error detected in HDF5 (version (number)) thread (IDs):
  #000: (file name) line (number) in H5Gopen2(): unable to open group
    major: Symbol table
    minor: Can't open object
  #001: (file name) line (number) in H5G__open_name(): group not found
    major: Symbol table
    minor: Object not found
  #002: (file name) line (number) in H5G_loc_find(): can't find object
    major: Symbol table
    minor: Object not found
  #003: (file name) line (number) in H5G_traverse(): internal path traversal failed
    major: Symbol table
    minor: Object not found
  #004: (file name) line (number) in H5G__traverse_real(): traversal operator failed
    major: Symbol table
    minor: Callback failed
  #005: (file name) line (number) in H5G__loc_find_cb(): object 'y' doesn't exist
    major: Symbol table
    minor: Object not found
h5dump error: unable to open group "/y"