What does this error code from Opayo mean?

I had an error code processing payments on Opayo and I want to understand what went wrong

If the payment gateway from Opayo My Sagepay is returned you can go to 

https://www.opayo.co.uk/support/error-codes

to check what the error code means. In most cases, it will be an incorrect character submitted that their gateway did not like. 

For Opayo Paytia is configured to pass

VendorData in the Paytia Account Number field 

VendorTxCode in the Paytia Reference number field

Opayo field Valid characters Max characters Notes
VendorData Letters, digits, and spaces 200 This is optionally used to pass any data you want displayed against the transaction in MySagePay.
VendorTxCode Letters, digits, hyphens, periods, underscores, and curly brackets 40 Your unique transaction reference. You must use a new and unique VendorTxCode for each transaction.