SYMPTOM
You are executing deliveries on a Runtime started on a Windows machine and nothing gets executed.
The sessions appear as prepared but stay in this state.
SOLUTION
The Windows cmd prompt has an option called 'QuickEdit Mode'. It can be enabled or disabled in the Properties of the cmd window.
When this is activated, the cmd will be paused as soon as the focus is done on it.
So if you click in the Runtime console, Windows will block it until the focus is released.
For example, we are here editing the console to copy something from the logs.
As a consequence, the console will be blocked by Windows until we use the 'ESC' key to stop focusing on it.
-> This is why the sessions stay in the prepared state.
-> If you unleash the console, all the prepared sessions will be executed.