Why is there an error with uploading photos to classmates?

Question

Classmates

Application made. The required rights have been obtained. Everything worked.
The essence of the application is posting from the site (php) text and pictures to a group.
After blocking and subsequent restoration of the account, at the stage of loading the post, I get an error:

array(3) {
  ["error_msg"]=>
  string(62) "one.image.server.upload.ContentUploadServerException: NO_IMAGE"
  ["error_code"]=>
  string(3) "505"
  ["error_data"]=>
  string(8) "NO_IMAGE"
}

I received the tokens again, rewrote them in the script.
UP: Hmm, technical support of classmates, you are a force. I have been waiting for a response to the mail for a month, this message has been a week. Keep it up.