Can't accept or deny meetings

Hello.

I have problems with the meetings using my Nokia Lumia. Sometimes, I can't accept o deny the meeting and I see the following message "(Bold) No se puede responder a la convocatorioa de reunión (/Bold) No pudimos enviar la respuesta. Intenta enviar el correo directamente al organizador de la reunión" (sorry, the message is in Spanish). Why happens this message? How I can resolve?

Best regards.