How to resolve the error when posting a new node with Image Field and Entity Reference?

Question

I'm trying to create a new node using Drupal 7 + Services 3. The node type is 'activity_photo' has an image field, and a reference to a node. This is what I'm posting to the service

{
 "type":"activity_photo",
 "field_node_reference":{
 "und":[{
 "target_id":"x (1273)"
 }]
 },
 "field_photo":{
 "und":[{
 "fid":"20077"
 }]
 }
}

The response is status 200:

{"nid":null,"uri":...}

My error log shows the following:

Notice: Undefined index: display_field in file_field_widget_value()

Warning: end() [function.end]: Passed variable is not an array or object in file_managed_file_validate()

Notice: Undefined index: nid in _node_resource_create()

Any help on how to proceed?

Answer 1

In the end I changed the entity reference field to select list and posted like this:

{
 "title":"test",
 "type":"activity_photo",
 "language":"und",
 "field_node_reference":{
 "und":[1273]
 },
 "field_photo":{"und":[{"fid":"8880"}]}
}

also, I found my own modules was implementing hook_form_alter for this form, and this had further complications to be addressed to get it to work. So any hook_form_alter is something to remember when looking for similar problems.