1, the U disk itself has a problem, you can contact the manufacturer after-sales treatment to solve;
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2, the audio file format is not correct, it is not identifiable format, it is recommended to refer to the instruction manual;
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3, the U disk reformat try, all clean up again;
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4, the data in the U disk may not have enough space, try to leave a capacity of about 1G out;
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5, USB flash drive into the computer, right click properties, change to FAT32 can be.