First, we can view a transaction report that only displays cardholders with Validation Error responses: 
  1. Click Transactions > Transaction Search
  2. Set the desired date parameters for the search
  3. Under Status use the drop down menu to select Validation Error
  4. Click Search
Then, we can view the exact error reason: 
  1. Click the 3 dots next to the transaction and select Details
  2. View the Gateway Result to see the full error message
We can export these results to cross reference with transactions in donor software to find credit cards that are currently on the blacklist. In order to remove cards from the blacklist please chat with support.

The two most common Validation Error messages are: