Second Player cannot be controlled when window is inactive

Hi,
I am currently working on a 2-Player Splitscreen Game.
Whenever I start a 2-Player Level the Full Screen Window is not set to active but I can still control the First Player (with either Keyboard or a Gamepad).

The second Player can only be controlled if a Mousebutton is clicked inside the inactive window.

How can I set the window to active automatically or how can I let the Second Player get Control in an inactive Window?

I tried using ‘Show Mouse Cursor’ on/off but it didn’t help.

I believe this was fixed, the fix will be in 4.8.

If yuour building from source you can try the fix out yourself as it’s quite trivial.

In :

 FSlateApplication::RegisterGameViewport(...)

add true as the last parameter on the following line:

 FReply Reply = FReply::Handled().SetUserFocus(InViewport, EFocusCause::SetDirectly, true);

I am only using Blueprints for, but thanks for the answer.
I found another solution though. Just set Focus To Viewport in your Level Blueprint an the Second Player can be controlled right away.

is there also an option to open another frame / window which holds camera output for a player or even just camere output? if yes how to do it?

Sorry I don’t know about that. I think it would be better if you’ll post that as a new question. Because this question of mine was already solved here, so don’t excpect a lot of answers.