Sorry, but you may need to provide a little more context here, especially if and how this relates to a MAGIX product, what version you're using and what you're doing to get that error message.
The files you got are probably in some digital audio format, possibly with somewhat higher specs than a standard audio CD, which I suppose is where your remark regarding "SACD quality" comes in. However, SACD is not a file format, and it uses a specific coding that is not PCM. The file would have to be in a specific file format, using a specific codec, e.g. WAV files using PCM, or maybe FLAC files. So, can you please them back in MP3 Deluxe(?) but not convert them to another audio format?