I'VE HAD SUCCESS....I tried just about everything mentioned on this forum and other posts. End result was so very simple I feel like a knob for not trying it earlier.
I moved the xpand2.big file into Programs (x86)/Common Files/Digidesign/DAE/Plugins.
The folder is full of .rsr and .dpm files, so putting .big in there seemed a little strange...but it worked for me.
It was that simple. Xpand2 is now playing and I'm a very happy chappy.
Hope it works for you.
Cheerio from Butugly.
