If the upload failes an Error Code is returned in the REST response format.

1: No image uploaded / zero filesize / general upload error (UPLOAD)
2: Developer API-Key has not been found (GENERAL)
3: User API-Key has not been found (GENERAL)
4: Content type has not been set (UPLOAD)
5: Invalid gallery ID (UPLOAD)
6: Secret is invalid (UPLOAD)
7: Image has been banned from Imagebam (UPLOAD)
8: File-extention is not allowed (UPLOAD)
9: File exceeded maximum allowed size (UPLOAD)
666: Developer API Key has been disabled by ImageBAM (GENERAL)