Make sure you're not using Ventoy. This sometimes prohibits accessing grub options in the proxmox installer. (7.3)
- Boot into the 'install proxmox' screen.
- Highlight 'install proxmox' and press 'e' to edit the boot options
- On line #4 (the line starting with 'linux', which has 'quiet' in it), add 'nomodeset' at the end
- F10 - save and exit
- Proxmox installer will continue to boot, and then fail because of some framebuffer error
- Ctrl-Alt-F1 to get root terminal
nano /usr/share/X11/xorg.conf.d/10-quirks.conf
and add: