If your printer can't read or open the sliced file exported from Lychee Slicer, there are a few possible causes:
1. USB stick or SD card issue The most common cause. Low-quality USB sticks (often included with budget printers) can corrupt data or fail after repeated use during long print jobs. We recommend using a quality branded USB stick of 16–32GB, formatted in FAT32 (some printers also support exFAT).
2. Wrong printer or file format selected With so many printers available in Lychee Slicer, it's easy to accidentally select the wrong one — especially for printers with similar names or multiple versions. Double-check that you've selected the correct printer and format. If the format you need isn't showing, try deleting and re-adding the printer to refresh its settings.
3. Defective USB port If no USB device is recognized by the printer at all, the issue may be with the printer's USB port itself rather than the file or stick.
4. Firmware update Printer manufacturers occasionally release firmware updates that can affect compatibility with Lychee Slicer without notifying us. If you recently updated your printer's firmware and the issue started after that, contact support at https://mango3d.io/contact-us/ and we'll look into it.
If none of the above resolves the issue, contact support at https://mango3d.io/contact-us/ with your printer model and file format.