Adding Features to layer error

[OisinSlevin]

Hi,
I keep running into this issue when trying to add polygons to my feature layer, 

My code basically pulls down a feature from a layer, 

modifies some of the text fields

then attempts to upload the feature to a different feature layer 

The same code works fine for line and point geometry data 

I also strip out any fields that are auto populated ex GlobalID and OBJECTID so this unique identifier is not something I feed in.

an_object={
"geometry":object.SHAPE,
"attributes":attributes
}
add_result=some_layers[6].edit_features(adds=[an_object])

{'addResults': [{'objectId': None, 'uniqueId': None, 'globalId': '09846522-E815-405F-98C5-22991AA70D59', 'success': False, 'error': {'code': 1000, 'description': 'Conversion failed when converting from a character string to uniqueidentifier.'}}], 'updateResults': [], 'deleteResults': []}

[OisinSlevin · Accepted solution]

Found the issue, The features layer had user attributes which were "esriFieldTypeGUID" and if you leave them null, but leave them in the "attributes" while adding them , then it throws this error.