Allow Empty Business Data Field
This option specifies whether to allow empty fields in task data:
-Dtask.data.allow.nulls=true|false
By default, -Dtask.data.allow.nulls=false, and Task Engine does not initialize business data if any of the sub-documents of business data is empty. If -Dtask.data.allow.nulls=true, business data is initialized even if sub-documents contain empty fields.