Worldpay Help

Load the two files
resultY.html
resultC.html
into the WorldPay Business Manager, Setup,  Payment pages, File Management.
These files are not used directly but their presence seems to be necessary to make the response templates default_worldpay_success.tpl
and default_worldpay_failure.tpl work.  Otherwise you get callback failure messages.

You need to set up in WorldPay Business Manager Setup, for Payment Response URL:  <wpdisplay item=MC_callback>
also the Payment Response Password and the MD5 secret as in the Admin page,
and Signature fields:    
currency:amount:testMode:instId     