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.
Had it myself but notice the Ver 2.1 software update for the A119S states-
6. Fixed: Camera freezing while showing XXXXX on screen
But remember updating the Viofo strictly requires the update file only and no other in the root directory of a freshly formatted card. It's best to always format the card in the camera, remove it then connect card via a reader to PC and download the update file directly to it, then remove card/reader safely from PC and insert back in the camera and power up and let it update and automatically delete the update file when finished and it will be good to go.
That's the best way to update and avoid glitches but should you get a lockup then power off the cam and remove and format the card via PC (exfat is fine for 64 or 128GB cards) and when you return it to the cam and power on it will want to format it again straight away. Then you can follow the update method above.
I said update but the same applies to refreshing/renewing current version installed software should the cam present any problems although you might want to format the card in the camera first as recommended periodically to see if that cures the problem you're having.