When I insert the CF memory card in the MW100, "E313" appears on the 7-segment LED. The user's manual says the cause could be a damaged or unformatted CF card, but the PC can access the memory card with no problem.

Check whether it is FAT16 (FAT) formatting. The MW100 can not read FAT32 formatting. FAT16 supports up to 2 GB, so use a CF card of 2 GB or less.