Mach2
I've got SONAR LE 8.5.1.17 with Windows 8
There may be a compatibility issue with the plug in. Isn't W8 64 bit? And my guess is that the older LE 8.5.1.17 is probably 32 bit. While the program may run just fine, the plugs (being 32 bit as well) may not be compatible with the 64bit OS... just a guess.