I was just messing around with my laptop trying to map keys from an external keyboard to bind to the hardware brightness control settings since some of the keys on my laptop's keyboard stopped working properly.
So following some of the instructions from another post on here, I added a couple lines into
/usr/share/X11/xkb/symbols/pc, and commented out what I thought to be the relevant lines. Clearly I made a huge mistake, because after I rebooted my laptop for the changes to take effect, none of the keyboard keys were working.
Even the onscreen keyboard looks super confused. All the character keys just show '?'s and the space bar says "No X keyboard found, retrying…"
Please help, otherwise I won't have any option but to reinstall from scratch on it.
I'm running Ubuntu Studio based on 19.04, on an Acer Aspire E1 model Z5WE3