Backup continue to fail

Why can I not complete the backup of my website? It keeps stopping to 50% on plugins.

It stops for a few minutes on 25% then at 50% it stops forever. I waited about an hr and still no progress beyond 50% so that is more than enough time to wait.

If you are going to tell me to disable plugins one by one and keep trying each time, sorry to say I do not have the time to spend performing lots of failed backups, enabling plugins each time. That is way more than the time I have on this project so hopefully this is due to something else.