API error codes

Guild or Character api errors

code message PHP constant
403 expired apikey RYAPI_ERROR_EXPIRED_KEY
404 invalid apikey RYAPI_ERROR_INVALID_KEY
503 cache not initialized RYAPI_ERROR_CACHE_NOT_FOUND

Error 503

This usually means that character which this key belongs to, has not logged into game yet. Logging into game fixes it.

Its also possible, that the time of request, server side cache was being updated (ie, old file deleted, new file not yet created).
Request again after short delay.