@sdetweil
Using parragon Linux software on PC ,Pi SD card plugged in deleted the rotate right file which I had created as per the magic mirror documentation. Now mirror back to normal and working. Will investigate why the rotate command on the desktop does not work .

@sdetweil
Do not know about ssh, before I put the file in the auto start folder I did use the desktop preferences to rotate screen it just went blank orange rebooting it went back to normal ( I believe it does that goes to default on startup) . Thinking it may be a graphics driver problem but how do recover to get a display again ( how do I delete the file I added). can you put the SD card in a windows PC and do it from there? Any help would be appreciated as I had just got the mirror set up nice for me apart from portrait mode don’t want to lose my settings….

April 2019, Release Date: 2019-04-08 Kernel: 4.14 to /etc/xdg/lxsession/LXDE-pi/autostart ):

nano ~/.config/lxsession/LXDE-pi/autostart
And add the following line:

@xrandr --output HDMI-1 --rotate right
After trying to rotate mirror to portrait mode with Pi4 added above line and now boots to blank orange screen . how do i get back to the mirror as no keys work ( mouse does ) any help appreciated as beginner to the Pi