MCPepsh

I actually have a pretty similar error on my X-S10 as well. I regularly run into write/read errors with all of my 3 different SD cards. I've done some tests today and got an interesting discovery: I can take 1001 photos without any problems and then get a write error . If I restart the camera I can take another 2 photos just to get the next write error. From then on, the problem is there to stay. Only formating the SD card fixes the issue ""permanently"" (it of course comes back after I take more than 1001 photos 🙄). Since I can take 2 photos without an error after the first error occured, I think the actual breaking point is at 999 pictures, not after 1001. That would fit to your case. Anyway, it does not matter, which folder the photos are in. In my experiment I crossed the folder limit once and it kept working for quite a while. Only after hitting >999 pictures in total (spread over the two folders) the first error occured. I already contacted Fujifilm support and they told me to try an officially compatible SD card first. Before both my cards where from a brand called "Peter Hadley" which seems to be a private label of some kind. So I got a SanDisk Extreme Pro 128 GB now but still get the exact same error. I think I will send it in to Fujifilm in hopes that they offer me a repair that I can (and want to) afford.