Hello,
I have encountered a bug in WACUP build #6800 (and earlier) in regards to SPC archives, or .RSN files. When attempting to open these files, they will appear in the playlist with the filename, and "(contains ## valid files)" appended to it. The individual songs are not expanded into the playlist and the file is not playable. Renaming the file to .ZIP makes the individual songs appear in the playlist as expected, but renaming a full collection of .RSN to .ZIP seems rather extreme to fix this issue.