I faced a "The system is running in low-graphics mode error" like the on in this question How to fix "The system is running in low-graphics mode" error?

This happened in Virtualbox!

I'll go with the answer that the root file system ran out of space since I left the system downloading some stuff & previously I was notified that the system is low on space. Dumb of me but everyone makes mistakes. I was planning on moving the files to a shared folder later on.

The screen I get is similar to the screen in the link above. If I click on Ok, I get the following screen

None of the options work. I even tried to use the shell mode to try to free some space but all I get is this screen

So my question is how can I get back to my system & move the files to the shared folder (which btw needs guest additions which is was already installed on the system!) or better (if easier) an USB?

Note: I tried a live mode (iso) but I cannot do anything (e. G; open nautilus or a terminal!); + I get a VERP_PDM_MEDIA_LOCKED_error when try to install guest additions.