JSON Key file error in Service Account Settings

I created a service account to connect this to your other plugins – Directory & Drive Embedder. On the Google Apps Login setup page, there is a place to upload a JSON file. I followed the directions on the documents, uploaded the file, and get this error:

JSON key file does not contain all of client_email, client_id, private_key, and type

I’m not sure what it means, or what I need to do within the Google service account to generate a file that would be acceptable.

Thank you for your help.