trying to plot WEIGHT column gives error

$ shadems ../msdir/1557766852_sdp_l0-kgb_cal.ms -x TIME -y WEIGHT -c ANTENNA1 --field J1939-6342
2020-11-18 11:55:07 - shadems - INFO - using colourmap colorcet.bkr
2020-11-18 11:55:07 - shadems - INFO - using colourmap cmasher.pride
2020-11-18 11:55:07 - shadems - INFO - using colourmap colorcet.glasbey_dark
2020-11-18 11:55:07 - shadems - INFO - /home/oms/.venv/sms/bin/shadems ../msdir/1557766852_sdp_l0-kgb_cal.ms -x TIME -y WEIGHT -c ANTENNA1 --field J1939-6342
2020-11-18 11:55:07 - shadems - INFO - ------------------------------------------------------
2020-11-18 11:55:07 - shadems - INFO - : MS ../msdir/1557766852_sdp_l0-kgb_cal.ms contains 1176690 rows
2020-11-18 11:55:07 - shadems - INFO - :   (1, 4096) spectral windows and channels
2020-11-18 11:55:07 - shadems - INFO - :   4 fields: J1347+1217 J1512-0906 J1331+3030 J1939-6342
2020-11-18 11:55:07 - shadems - INFO - :   28 scans: 3 5 7 9 11 13 14 16 18 20 22 24 26 27 29 31 33 35 37 39 40 42 44 46 48 49 51 52
2020-11-18 11:55:07 - shadems - INFO - :   60/60 antennas: 0:m000 1:m001 2:m002 3:m003 4:m004 5:m005 6:m006 7:m007 8:m008 9:m009 10:m010 11:m011 12:m012 13:m013 14:m015 15:m016 16:m018 17:m019 18:m020 19:m021 20:m022 21:m023 22:m025 23:m026 24:m027 25:m028 26:m029 27:m030 28:m031 29:m033 30:m034 31:m035 32:m036 33:m037 34:m038 35:m039 36:m040 37:m041 38:m042 39:m043 40:m044 41:m045 42:m046 43:m047 44:m048 45:m049 46:m050 47:m051 48:m052 49:m053 50:m054 51:m055 52:m056 53:m057 54:m058 55:m059 56:m060 57:m061 58:m062 59:m063
2020-11-18 11:55:07 - shadems - INFO - :   1830/1830 baselines present
2020-11-18 11:55:07 - shadems - INFO - :   corrs/Stokes XX XY YX YY I Q U V
2020-11-18 11:55:07 - shadems - INFO - ------------------------------------------------------
2020-11-18 11:55:07 - shadems - INFO - : Data selected for plotting:
2020-11-18 11:55:07 - shadems - INFO - Antenna(s)       : all
2020-11-18 11:55:07 - shadems - INFO - Baseline(s)      : all except autocorrelations
2020-11-18 11:55:07 - shadems - INFO - Field(s)         : J1939-6342
2020-11-18 11:55:07 - shadems - INFO - SPW(s)           : all
2020-11-18 11:55:07 - shadems - INFO - Scan(s)          : all
2020-11-18 11:55:07 - shadems - INFO - Channels         : all
2020-11-18 11:55:07 - shadems - INFO - Corr/Stokes      : XX XY YX YY
2020-11-18 11:55:07 - shadems - INFO - ------------------------------------------------------
2020-11-18 11:55:07 - shadems - INFO - loading minmax cache from 1557766852_sdp_l0-kgb_cal-minmax-cache.json
2020-11-18 11:55:07 - shadems - INFO - axis: TIME(TIME), range (None, None), discretization None
2020-11-18 11:55:07 - shadems - INFO - axis: _(WEIGHT), corr False, range (None, None), discretization None
2020-11-18 11:55:07 - shadems - INFO - axis: _(ANTENNA1), corr False, range (None, None), discretization 16
2020-11-18 11:55:07 - shadems - INFO -                  : you have asked for 1 plots employing 3 unique datums
2020-11-18 11:55:08 - shadems - INFO - : Indexing MS and building dataframes (392940 rows, chunk size is 5000)
Traceback (most recent call last):
  File "/home/oms/.venv/sms/bin/shadems", line 7, in <module>
    exec(compile(f.read(), __file__, 'exec'))
  File "/home/oms/projects/shadeMS/bin/shadems", line 8, in <module>
    main.main([a for a in sys.argv[1:]])
  File "/home/oms/projects/shadeMS/shade_ms/main.py", line 675, in main
    row_chunk_size=options.row_chunk_size)
  File "/home/oms/projects/shadeMS/shade_ms/data_plots.py", line 193, in get_plot_data
    value = axis.get_value(group, corr, extras, flag=flag, flag_row=flag_row, chanslice=chanslice)
  File "/home/oms/projects/shadeMS/shade_ms/data_mappers.py", line 358, in get_value
    raise TypeError(f"{self.name}: unexpected column shape")
TypeError: _:WEIGHT:False:(None, None): unexpected column shape
(sms) oms@simon:~/projects/OldDevils/cc-polcal$
ratt-ru / shadeMS

trying to plot WEIGHT column gives error #82
