Hello,
After further investigating this issue, we came to the conclusion that this is actually the intended behavior.
During a silent installation, no UI should be spawned, even the one spawned by a Launch Condition. Therefore, the behavior is normal, taking in consideration that when the launch condition is evaluated, the UI Level is set to "silent". For more information about this, please have a look on the following thread:
viewtopic.php?f=2&t=36032
As you can see, the fact that the Launch Conditions was spawned during a silent install was a bug we have faced in the past and which was fixed.
However, we found an issue in what regards this. It seems that the process is launched and somehow hangs. It can only be stopped by using the Task Manager to end its process.
By default, the process should terminate automatically (this is the way Windows Installer handles this).
We will further investigate this and will update this thread as soon as a fix will be available.
Best regards,
Catalin