SFZ file error

I have been getting an "unknown file type" error when I try to load files. (other than SSO) I have read as much as I can find on editing the text file and linking the wav sample. I used some SSO files as a model. As I understand it, you need a path and a sample for Msc in the same folder. I cannot figure out what is "unknown" about it. I have some single shots with a single region and a lokey-hikey and pitch center. That's it. Could it be rejecting acidized wav files or the Aria conversion? (inside Sforzando) If so, I can try to write them from scratch with an sfz extension and the raw wav linked. Any suggestions?