Tvheadend

Hi sinse I cant use apt-get update/upgrade
I wonder if ther is another way to upgrade manually?
any toturials??

Im using ubuntu "xenial"

Err:1 https://dl.bintray.com/tvheadend/deb xenial/stable-4.2 amd64 tvheadend amd64 4.2.6-84~g81f56cc~xenial
404 Not Found
E: Failed to fetch https://dl.bintray.com/tvheadend/deb/pool/4.2/tvheadend/tvheadend_4.2.6-84~g81f56cc~xenial_amd64.deb 404 Not Found