Hello, it seems this question gets asked fairly regularly here, but I failed to find any usable information in the forum or on the developer pages. Any transaction I try to process through a hosted pay page responds with an ERROR message and Response Code 959. I've tried using both MasterCard and Visa from here: https://developer.moneris.com/en/More/Testing/Testing%20a%20Solution
Typical response looks like this:
I'm trying to go through Store 2.