I am unable to post image references I have had this module working for years. Recently, it has stopped working. I'm using Services 3 to:

Log in and get a token
Create an image file and get its file ID
Create a node, using the file ID from the previous step for the image field

The JSON I'm posting for the image field on the node is similar to the following.
   &quot;field_image&quot;:{  
      &quot;und&quot;:[  
         {  
            &quot;fid&quot;: 10279
         }
      ]
   }

Suddenly, I can't get the node I'm creating to reference an existing field via the file ID. The node and the image are created without issues, but the image field is empty.
Is there some other way I should be doing this?
This seriously worked for years, so I'm not sure what changed.
I am using the Services module 7.x-3.27.
Turns out you need a patch. Field was multi-value.
https://www.drupal.org/project/services/issues/2224803