1.Check if your Gcode file is in the subfile . if yes, Pls put the Gcode file to the root directory
2.Check if your file is G-code .Because only the G-code files and can be printed .
3.You may try to reset the SD card and " click "Init. Media ",Or you may reboot the machine .(Artist-D )
4.You may choose the "FAT32" to format the SD card and slice again .Or you may change the SD card .
5.If what listed above doesn't work, it is possibly that there is a problem in SD card slot. Please contact with our after sales :email@example.com