The camera havs been working great, but I got a problem last weekend, camera kept stoping recording, later on I found out camera complained SD to slow to keep up. After re-format SD, the problem went away. I bought SAMSUNG PRO Plus + Reader 256GB microSDXC Up to 160MB/s.

I don't know if it was a camera or SD card issue?

If you get that error again, try with another brand of microsd.

Most often it will be the card that is actually for slow, but after your format it could have been just really fragmented so a format fixed it

With all my cameras I tend to format card (in camera) after every time I downloaded recent material - it is generally best practice rather than just deleting files.
When you only delete, other hidden stuff like indexing information can remain which is eventually able to mess things up.

Thanks for all the replies, although I only used about a month, I did delete files. I will reformat every time from now on after backup the videos to maintain good status of SD card.

Hi there. Thank you for reaching out. This error message normally appears due to a slow SD card. If the original high-speed SD card is used, reformatting the card will normally isolate the issue. If the issue persists, we highly recommend using a different SD card. You may refer to the image below. Thank you for your understanding and support.