Jun 17 18:09:46 unRAID kernel: FAT-fs (sda1): Directory bread(block 15303) failed
Jun 17 18:09:46 unRAID kernel: FAT-fs (sda1): Directory bread(block 15304) failed
Jun 17 18:09:46 unRAID kernel: FAT-fs (sda1): Directory bread(block 15305) failed
Jun 17 18:09:46 unRAID kernel: FAT-fs (sda1): Directory bread(block 15306) failed
Jun 17 18:09:46 unRAID kernel: FAT-fs (sda1): Directory bread(block 15307) failed
Flash drive problems, you can first try backup and reformatting it, if more issues you should replace it.