I managed two times to get my Chrome browser open up invisible.
I saw the application open in the taskbar but when clicking it nothing was shown.
In the small preview I could even tell that the chrome window still reacts to shortcuts like to open a new tab.
The first time I ended up reinstalling Chrome and deleting my entire profile.
The second time I was pretty sure I used keyboard shortcuts and one of them must have let my browser window go invisible.
Long story short, it turned out, five monitors (I actually have two) were registered inside windows and by pressing Shift+Windows+left, I moved the Chrome window to a monitor that does not really exist. It was active there but invisible to me.
Solution: Pressing Shift+Windows+right let it appear again.
Deutsch – die Lösung: Feststelltaste+Windows+rechts drücken, um das Chrome-Fenster auf einen der tatsächlich sichtbaren Monitore zu bringen.