I am not new in MGET and have worked a reasonable amount of time on some tools. I've been having a problem in the create fishnet tool that I have never had before. Hope you can help me.

When I input all the parameters in the appropriated boxes (x and y coordinate of the fishnet corner (SIRGAS 2000 datum), cell width and height (0.009), number of columns and rows (40), etc), I got the following error:

Executing: ArcGISFishnetsCreateFishnet "C:\Users\rhtar\ArcGIS\toc.shp" "GEOGCS['GCS_SIRGAS_2000',DATUM['D_SIRGAS_2000',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]];-400 -400 1000000000;-100000 10000;-100000 10000;8.98315284119521E-09;0.001;0.001;IsHighPrecision" -49.606 -2.301 "Lower Left" 0.009 0.009 40 40 # Fail # # # # # CellID CellCol CellRow CellArea # 0 0 0
Start Time: Wed Aug 14 12:15:29 2019
Running script ArcGISFishnetsCreateFishnet...
Inserting 1600 fishnet cells.
RuntimeError: This cell cannot be inserted into ArcGIS ShapeFile "C:\Temp\GeoEcoTemp_rhtar\tmppimxui\Fishnet.shp" because field CellArea has not been assigned a value and it is not nullable. You must provide a value for this field.
Failed script ArcGISFishnetsCreateFishnet...

Traceback (most recent call last):
  File "C:\Program Files\GeoEco\ArcGISToolbox\Scripts\ArcGISFishnetsCreateFishnet.py", line 5, in <module>
    ExecuteMethodFromCommandLineAsArcGISTool('GeoEco.SpatialAnalysis.Fishnets', 'ArcGISFishnets', 'CreateFishnet')
  File "C:\Python27\ArcGIS10.6\lib\site-packages\GeoEco\ArcGISScripts.py", line 210, in ExecuteMethodFromCommandLineAsArcGISTool
    exec sourceCode in globals(), locals()
  File "<string>", line 1, in <module>
  File "C:\Python27\ArcGIS10.6\lib\site-packages\GeoEco\SpatialAnalysis\Fishnets.py", line 354, in CreateFishnet
    cur.InsertRow()
  File "C:\Python27\ArcGIS10.6\lib\site-packages\GeoEco\Datasets\__init__.py", line 2535, in InsertRow
    raise RuntimeError(_(u'This %(singular)s cannot be inserted into %(dn)s because field %(field)s has not been assigned a value and it is not nullable. You must provide a value for this field.') % {u'singular': self._RowDescriptionSingular, u'dn': self._Table.DisplayName, u'field': f.Name})
RuntimeError: This cell cannot be inserted into ArcGIS ShapeFile "C:\Temp\GeoEcoTemp_rhtar\tmppimxui\Fishnet.shp" because field CellArea has not been assigned a value and it is not nullable. You must provide a value for this field.

From what I understood, the error seems to be in the field 'CellArea', which is an optional field to inform the name of the field (not a number - I have tried to put any number with no success). In all previous analyses that I created fishnets, I never filled this field. I can't figure out what is wrong. I tried to change the datum and other values but I still got the same error. 

Do you have any thoughts on what happened?

Thank you in advance,

Rodrigo