1. First, make sure that the sd model file has no damaged or missing parts, and the path of the sd model file is correct without any special characters or spaces.

2. Secondly, check whether the sd card is inserted correctly to ensure that the sd model file format is correct and compatible with the device.

3. Finally, try to restart the device to ensure that any errors or conflicts have been resolved. The above solution is invalid. Please contact the equipment manufacturer or sd model developer for further assistance.