Fatal Error After installing Cross Sell - Just Another Cross Sell Mod

Yikes, here's my error message when I try to log on to my zen admin:

Fatal error: Class 'yclass' not found in /......./includes/functions/extra_functions/xsell_advanced.php on line 18

I just installed Cross Sell - Just Another Cross Sell Mod and not only can I not log on to my Admin my website comes up online but none of the individual products pull up all I get is a blank page??

PLEASE HELP ME!!

Okay, I was able to get my site working properly showing the products but I am still not able to log on to my Admin ? I hope someone can help with that fatal error!! Pretty please?

This version of Cross Sell I believe requires the Module Manager to be installed ...

The new Multiple Cross Sell does not ...

Thanks so much for offering to help me!! I did install Module Manager however, I went back to recheck all my files and some were not installed and some were in the wrong place. I corrected these errors but I am still not able to log in to my Admin area I keep getting the error?

Sounds like you have still have files in the wrong place or missing or corrupt on the server ...

First check that the Module Manager is installed properly ...

Then check that the cross sell is installed correctly ...

okay, I have gone back and removed all the files from the cross sell and my admin works... Under Tools I see the Module Manager and when I click on it I do not get any errors... Back to square 1

I have downloaded "Cross Sell Just Another Cross Sell Mod" is that different than the one you mentioned? If so do you happen to know where in this forum I can find a download?

I really need/want a Cross Sell module and am willing to work hard and do plenty of research to get it!! I really appreciate all you help:yes:

I was thinking of Multi Cross Sell add on;
http://www.zen-cart.com/index.php?main_page=product_contrib_info&products_id=1677

Thanks so much ! I will check that out!!