As soon as the problems started I checked my HD connectors and memory card connectors. That made no difference. I ran Spinrite on my HD and it reported no problems.I rebooted. When “Started Local Service” appeared on the screen it turned black. After a long wait a prompt returned and told me that there was a problem on /dev/sda5 which is my /home partition and suggested I log in as root to view journalctl -xb. It showed errors on that parttition and suggested I should fsck it which I did, allowing all the corrections. I can reboot now, but all my favorite applications are missing from my panel and a number of mystery files have appeared in my home directory. Their names are…
I would make sure that any important data is backed up. Speculation here, but perhaps there was some kind of power transient/brown-out that caused the filesystem corruption?
Thank you for that suggestion as I believe it to be the most likely. Someone is electro-welding next door and here in Mexico we run on very low amp house service.