Old Montage with sd2-files doesn't open

I have some old projects, created in WL7 on Mac, which use sd2 source files. (Yes, their resource forks are intact, and they are stored on drive in MacOS Extended format.)

WL doesn’t load the old sd2 files, in fact I cannot open those sd2 files at all in WL, neither in 7 nor in 10.

Other montages with sd2 files seem to work, what is going on?

Try with open as “Special File Format” and use Big Endian (Motorola)
and then convert SD2 to wav it’s more useful this days.

regards S-EH