When launching the Payment Terminal, a loading screen will be shown, followed by the Dashboard. Prior to/during/immediately after this process (depending on the specific version of the Payment Terminal), the Payment Terminal may close without any warnings or dialogs.
The Payment Terminal will close itself if another running instance of the Payment Terminal is detected on the computer, in order to prevent issues in processing. On multi-head/multi-seat environments, this will prevent multiple users from using the Payment Terminal at once (unless configured otherwise).
This is generally caused by a hung program, and/or a configuration error. Below are a variety of solutions to this issue.
Kill hung copies of the Payment Terminal
1) Open an administrative command prompt.
Open the Start Menu, type
cmd, and press Ctrl-Shift-Alt-Enter. If prompted, enter the Windows credentials of a user with administrator privileges. A Command Prompt window should appear.
2) Stop currently running Payment Terminal processes.
In the prompt, type
taskkill.exe /im Payment_Terminal.exe /f, and press Enter. This will stop any currently-running copy of the Payment Terminal (hung or not).
Reopen the Payment Terminal - it should open as normal.
(Server only) Enable server mode
This is only recommended if this is a multi-user, multi-seat environment (i.e. using Remote Desktop, Citrix XenDesktop, or others).
The Payment Terminal needs to be configured for operating on a server. The procedure to accomplish this is mentioned in the installation guide.