Updater app runs into timeout

  1. click Download now , just download .zip file use your computer.
  2. use scp copy .zip file to your server /var/lib/nextcloud/data/updater-[random string]/downloads/ .
  3. update /var/lib/nextcloud/data/updater-[random string]/.step change start to end
  4. Open Updater again, and click continue on top

check this blog