How are you trying to update? Is TB doing this automatically or are you trying to do this manually?

Hello, thanks for answering. I always do it manually.

It would be better to go to Help/About Thunderbird and allow TB to automatically update. Let us know if that doesn't work and any error messages you get.

Creo que no me he explicado bien, lo siento. Sí, eso es lo que hago, abro Thunderbird y me voy a ayuda, acerca de... Inmediatamente, intenta hacer la actualización pero me sale mensaje de error. Gracias!