'An unknown error has occurred.' when updating facebook group cover_url

Question

How to successfully update facebook cover_url group via api chart? No matter what I try, I get an error message in the third step from below:

• Create a group by POST /APP-ID/groupsDOCUMENTATION: https://developers.facebook.com/docs/graph-api/reference/v2.5/app/groups#publish
• Get returned GROUP-ID
• Using the same access_token, POST /GROUP-IDwith cover_urlparam DOCUMENTATION: https://developers.facebook.com/docs/graph-api/reference/v2.5/group/#update

The error I get is of the form:

{
   message: 'An unknown error has occurred.',
   type: 'OAuthException',
   code: 1,
   fbtrace_id: <SOME-ID>
}

I imagine some kind of restriction on valid covers, but neither the documentation nor the error gives me any indication as to what it is.

facebook , facebook: https://developers.facebook.com/bugs/425584494232936/

Answer 1

, facebook api.