Lo use por mucho tiempo, muy efectivo , pero ahora me aparece a todo lo ancho de la pantalla la leyenda que no esta actualizado, que lo deshabilite ,no lo he desabilitado ,trato de instalarlo y me dice que fallo la descarga que compruebe mi conexion. Saludos.

It's working again, thank you for fixing the issue so quickly. This is the best ad blocker by far.

If message "Download failed. Please check your connection" appears, try to update Firefox. Go to "Help" -> "About Firefox". Update to ver. 66.0.4 and restart Firefox.
Your addons can be enabled now. Works fine for me.

Thank you!

This is the best of its kind. Thank you @gorhill