When I want to edit an existed mapping after close DataMapper, mapping details (CopyTo, Repeat, Split) are missing. This happens only when I map to an field of array. See video below: video.webm To workaround for this is to delete that affected mapping and define it again. The default postrgesql connection is used as a source (select * from todo) + split step AMQ step is used as a target with JSON instance e.g. { "officeNumber" : 1, "arr" : [ { "name" : "test1" , "surname" : "surname1" , "addresses" :[ { "street" : "street1" }, { "street" : "street2" } ] } ] }