Message
The following fields are not editable and will be dropped: <fields>
Description
Dropped fields are fields that are present in the data pipeline but their values will not be written to the layer or table to update because the fields are set to not editable.
System managed fields are not editable and will be written with system managed values. For example, OBJECTID and GlobalID are system managed fields.
Fields that are not system managed and set as not editable will be updated with, appended to, or replaced with null values.
Solution
System managed fields can not be set to editable and will always be updated with system managed values.
To update, append, or replace values in noneditable fields that are not system managed, you must set the field to be editable. To learn more about setting editing properties on fields, see Control edits on a per-field basis.