I have an integration test to make sure ad creation works, but it started to fail on May 1st. The only failing call is ad creative creation. Reading still works.

Endpoint : act_{ad_account_id/adcreatives Method: POST

Response:

{
  "error": {
    "message": "Application does not have permission for this action",
    "type": "OAuthException",
    "code": 10,
    "error_subcode": 1341012,
    "is_transient": false,
    "error_user_title": "No permission to access this profile",
    "error_user_msg": "You don't have the required permission to access this profile",
    "fbtrace_id": ""
  }
}