I just had the same problem! On a fresh install of Zen I installed the Module Manager first (and it seemed to work fine), then I installed "Cross Sell - Just Another Cross Sell Mod" module. I followed ALL the instructions to a tee and I get the damned error Fatal error: Class 'yclass' not found in . . . /admin/includes/functions/extra_functions/xsell_advanced.php on line 18!!!

So I read through this forum post and someone had said that you must first install the original cross-sell mod, then the second "Advanced Cross Sell" mod, then the Module Manager mod, and finally this mod. Seems CRAZY -- but I did just that. Things worked fine with the install of the first two mods and module manager, but when I installed this one again it gave me the SAME DAMN ERROR!!! Ugghh :-(

Now, I have two questions:

(a) Why is this soooo complex? Can someone combine these mods so we have one working mod that is "perfect". This would be a great contrib if someone could do that. :-)

(b) What are the advantages of this mod versus just stopping at the Advanced Cross Sell mod?!? Am I really missing out if I just leave it at that and call it a day?

~ Thanks!