I know I'm waaaaay late to party, but here is my answer:
If you can't change screen resolution from display menu, try changing it from Terminal! (Command-Line).
You can achieve this by running these commands:
Enumerate the names of all your video outputs, and the possible resolutions for those currently connected to a monitor:
xrandr -q
Choose the name of the output you wish to change the resolution of, and:
xrandr --output <OUTPUT> --mode 1024x768
Note: If running from a text terminal, that is not running in gfx environment, you'll have to add a -d :0
parameter, i.e:
xrandr -d :0 -q
xrandr -d :0 --output <OUTPUT> --mode 1024x768
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