UEditor 4.5 window focus problems

Unreal Editor 4.5 has various windowing problems on Linux. One of them is that if I open another window the main window won’t receive mouse events even when alt-tabbing back to it. The clicks go to the newest window.

OS: Ubuntu 14.04

UE-version: git 4.5.0-release

CC: clang-3.5

Steps to reproduce:

  1. open a project in editor
  2. double click on a blueprint to open it in a new window for editing
  3. alt-tab back to the main window
  4. try to do something in the main window

This is a known issue with Slate and SDL2, and unfortunately there’s no solution at the moment as more work needs to be done on both aforementioned modules.

As we (the Linux community together with Epic) continue to work on refining the Linux UE4 Editor, it is an ongoing problem that will need to be addressed very soon as it otherwise makes the Editor unusable, in my humble opinion.

Thanks for the answer. It’s one of the most frustrating bugs at the moments for me. Hopefully there’ll be a solution in the near future.