1) Individuals have their own robots. For example, everybody gets their own automated hydroponic garden, enough to provide them with sufficient calories.
2) A dictatorship seizes control of the automation and lets the people starve.
I think it's very unlikely that we'll have a welfare-capitalist society where major corporations own mass automation, where the government taxes the corporation so highly that government can pay for everyone else to survive.
Taxing mass automation to pay for basic income is just too fragile. If the people themselves aren't providing wealth through productive labor, then at some point, somebody will try to starve them instead of feeding them, and they'll succeed.