Here is further detail.
I added a call to :account/account_media in hopes that that was the missing link.
i get similar results
I post the image to uploadmedia
POST /1.1/media/upload.json
{“image”:{“w”:320,“h”:50,“image_type”:“image/png”},“size”:18962,“media_id_string”:“702530820502745089”,“media_id”:702530820502745089,“expires_after_secs”:86400}
i got back the media id and it has the correct size
POST /0/accounts/xxxxx/account_media?creative_type=BANNER&media_id=702530820502745089
So now i post that id to account_media immediately following the response from the upload
{“request”:{“params”:{“account_id”:“xxxxx”,“creative_type”:“BANNER”,“media_id”:702530820502745089}},“errors”:[{“code”:“INVALID_MEDIA_ID”,“message”:“Media referenced by media_id 702530820502745089 was not found.”}]}
and here is the createcard response called immediately after
{“request”:{“params”:{}},“errors”:[{“code”:“NOT_FOUND”,“parameter”:“image_media_id”,“message”:“702536535334264832 was not found”}]}
but, if i make the image small than 800px wide i get this response from create card
{“request”:{“params”:{}},“errors”:[{“code”:“INVALID_IMAGE”,“parameter”:"",“message”:“The image should be wider than 800 pixels”},{“code”:“INVALID_IMAGE”,“parameter”:"",“message”:“The image should be taller than 200 pixels”}]}
So i increase the image size to over 800x200
and i am back to this
{“request”:{“params”:{}},“errors”:[{“code”:“NOT_FOUND”,“parameter”:“image_media_id”,“message”:“702539438123954176 was not found”}]}
Something tells me the error messages i am getting are misleading?