My Viofo A119 camera got it's firmware corrupted. I solved the problem, but there are some lessons to be learned.
The problem presented itself when I powered the camera and it does not start recording and displays a line of crossed squares on the bottom left side of screen. The buttons do not work, not even power off.
I removed the card and the camera showed the "insert card" message; the buttons work.
I took the camera home and checked the issue online. I found nothing on Viofo forum but Google sent me to Reddit where I found the firmware corruption is a common bug on Viofo cameras.
I checked the card for errors (chkdsk) and there were none. However, and found 3 new files in root (pmp_usb.ini, winamp_metadata.dat and winamp_metadata.idx). I remembered the previous day I had the card inserted into a card reader and I used Winamp for some music. Winamp wrote the 3 files on card and it looks like when I put the card back in camera the things got nasty.
I reinstalled the firmware, and the problem went away.
I don't know if the 3 files caused corruption, but the two events are correlated and worth investigating.