Customer Query: 

if the customer is using Cayan Payment Processor before 6.6 and if the customer decides to upgrade to Ivend version 6.6.

Will Cayan Payment Processor be compatible with version 6.6 ?

Support Comment: 

Cayan payment processor is supported in iVend 6.6 version. Once a customer upgrades to iVend 6.6, the compatible DLL also will be updated.

Note: As a standard practice it is always recommended to first perform the upgrade in a test environment and once all the business cases are successfully tested, then only upgrade to production environment