Starting-Problem - UE4

Hello,
I downloaded Unreal Engine (Creator) yesterday. Then I downloaded the Epic Games Launcher and installed Unreal Engine 4.26.1…
Clicking on Start/Launch should open the project manager, right?
Instead the launcher is closed and nothing happens. Also with the previous version (4.25.4) it didn’t work…

Did I make any mistake or how can I solve this problem?