Hi,
the error string do not appear in the translation files of MapStore, but I see you customized MapStore, so probably you may have customized also this error string (by the way, you can contribute to improve translations, if you found errors or you want to add new languages).
A similar one seems to be ""La solicitud de DownloadEstimator falló, lo que significa que el archivo exportado excede los límites del servidor configurado. Intente cambiar las opciones de descarga o agregue un filtro a su capa y vuelva a intentarlo.""
This error happnes when download estimator fails. Typically it fails when the request overflows the limits. See documentation of the Download estimator" and Download Process of GeoServer here to configure it:
Because you customized MapStore, probably you are able to get the exact error from HTTP requests, to confirm the error is the one you expect.