I am certainly not an expert, but I suppose you can do the following to clean your SD-card:
- put your SD-card into a reader and delete the files/maps in your card.
- format your card with your pc/laptop. It doesn't matter in which format FAT32 / FAT16 / NTFS /... It is just for cleaning up your SD card.
- after formatting, put it into your X1 and format your SD card again with your X1 in System settings (storage formatting). This time your card will be in the correct format, necessary for your player.
- then connect your player with your computer and you will find an empty map where you can put your music.
- disconnect the X1, update your media library in System settings
- and normally everything should be working.
Be aware that your music should be ripped correctly. When you music is not ripped correctly, your device could hang up because it can't read the file (mp3, flac, alac, ...) as it should.
Well I tried this: formatted my SD, then put it in X1, format again, then connected but my pc says that I have to format in order to use it. I try to format but it says unable to complete format :/