Unable to change screen settings on Linux Mint (SettingsDaemon was not provided by any .service files)

I received this error because cinnamon-settings-daemon was not running. You can check if it is running as the following command will list it:

pgrep -fa cinnamon-settings-daemon

If cinnamon-settings-daemon appears in the output of the above command then your issue is different to mine. Otherwise, run it from the terminal as follows:

cinnamon-settings-daemon &

This should enable you to change the screen settings.

Out of interest, cinnamon-settings-daemon wasn't starting on login because of this issue. Doing the following and then running cinnamon-settings-daemon fixed it for me:

rm -f ~/.config/monitors.xml{,.backup}