Drop down menu not work as expected in Windows 10 Insider preview 14915 and up

All File Menu is broken + DropDown Menu not work in any window (File Menu, Toolbar, Viewport, anywhere where is placed drop-down arrow).
Affected UE4Editor (4.12.5 and 4.13) and “Epic Games Launcher”.

On the same PC but with Win8.1 Pro and UE4.12.5 all is ok!

Avi file for demonstration of the UI BUG in Windows 10 Insider Preview

The BUG is visible in any drop-down or down arrow control:

-drop-down menu of File Menu;

-toolbar buttons with down arrow;

-down arrow in viewport window;

Little trick to show drop down menu on File Menu: click on File and then press SpaceBar.

Maybe this BUG rise if you have Windows 10 Pro insider preview > 14393 + UE4.>= 4.12.5

[More info and screenshots here][1]

This BUG is confirmed and in W10.14926.1000 Pro Insider Preview 1607. All File Menu is broken + DropDown Menu not work in any window (Toolbar, Viewport, anywhere where is placed drop-down arrow)

Check avi file in zip attachement [link text][3]

This BUG is confirmed and in W10.14931.1000 Pro Insider Preview 1607. All File Menu is broken + DropDown Menu not work in any window (Toolbar, Viewport, anywhere where is placed drop-down arrow)

Thanks to manoelneto, the solution for this BUG is found:

In “Engine\Source\Runtime\Core\Private\Windows\WindowsWindow.cpp” locate and comment (turn off) the following line:

  • WindowExStyle |= WS_EX_COMPOSITED;

Then Build UE4 (again)!

Tested and confirmed on W10.14931.1000 Pro Insider Preview 1607 and in UE4.12.5+UWP and in UE4.13.

More details here

#High Contrast Theme

When I encountered this issue here is the solution I figured out, and this was the only thing I had to do.

This solution does not require using a custom engine build, you can do this with a release / launcher build

Overview: Use one of Windows10’s high contrast themes

How To:

  • Do a search in windows start menu for “high contrast”

  • Select one of the high contrast themes from the drop down or tiled list depending on your OS version. You can customize these themes!

  • Click Apply

Now you will find all of the drop downs in UE4 that were either slow or not appearing at all will now work perfectly again.

#:heart:

Rama

Such an odd and annoying work-around…but it works! Saved me. Thanks, Rama.

This seems to work for everyone, problem is i’m not the sharpest. So when you say, locate and comment or “turn off” the line, I don’t completely understand. Could you help me out with this, or make a short video. It’d help quite a bit.

Thanks to Rama for a temporary fix. It works, although its an eyesore for the rest of windows functions.

this bug is still an issues in the UE 12.5 version. Not even the “WindowExStyle |= WS_EX_COMPOSITED;” fixes it. Only the High Contrast solution will fix this. Kind of annoying if one really wish to use the UE4 12.5 engine version on Windows 10. Sigh…

All you gotta do is put a // at the start of the line.

Sorry, How can I compile the source code? The tutorial says I have to generate .sln with GenerateProjectFiles.bat, and when I use source code from C:\Program Files\Epic Games\UE_4.12\Engine\Source and .bat copied from github, it says it’s not root directory.