A: You may see the error "Transaction could not be canceled" even when the transaction actually gets canceled so it may have actually worked.
The 409 error also comes when the second transaction starts before the earlier one times out so that may be the issue as well and is now fixed. Please check with the clinic to see if they can charge again.
A: The problem is that you're running a multi user configuration on a Windows machine, and then trying to run a service that uses blocking calls across multiple user accounts without using group policy editor for process control. A windows SA, or MCSE would be able to sort this out as it is a common task for a windows systems admin.
In windows, you need to use the group policy editor and define a script to be run before logout (gpedit.msc -> User Conf -> Windows Settings -> Scripts -> Logoff). You need to point it at a powershell script that can be as simple as the one liner:
taskkill /IM AnyPayCloudBridge /F
In group policy editor, set a script for pedit.msc -> User Conf -> Windows Settings -> Scripts -> Logon
Start-Process -FilePath "C:\Program Files (x86)\AnywhereCommerce\AnyPay Cloud Bridge.exe"
More on group policy editor and how to use it to manage login and logout events can be found here:
And various sample scripts can be found here:
If you know a local MCSE or Windows Admin, we can prompt them for advice. They can probably set this up for your clinic in 5 minutes.