upgrade - The system is running in low graphics mode. How do I fix this?

I was updating ubuntu from 14.04 to 16.04. Somewhere in between the system restarted and the following message came up:

The system is running in low graphics mode. Your screen, graphics card, and input device settings couldn't be detected correctly. You will need to configure these yourself

I went to failsafe recovery following the question "How to fix "The system is running in low-graphics mode" error?" but I was unable to open the terminal.

How do I fix it??