[UMG] Spinbox unclickable after forced lost focus

edited: I can confirm this happening on 4.18.1 as well. The spinbox is unable to regain focus if it was lost while spinning.

Good catch.

System: Windows 10

Engine Version: UE 4.17.2

If the user focus is lost/changed while mouse dragging a UMG spin box the spinbox becomes unusable. (Unable to click/drag with the mouse).

The user focus can be lost (before letting go of the mouse button) in 2 ways:

  • by calling: Set Input Mode.
  • Alt-Tabbing

I managed to reproduce this in a clean 4.17 windows project.

Steps to reproduce:

  1. Create a new project
  2. Create an UMG widget blueprint
  3. Drag a spin box onto the canvas
  4. Save & Compile
  5. In level blueprint add the attached blueprint code. (Create, Add widget, Set input mode)

  1. PIE
  2. Start dragging the spinbox and press Z (or alt-tab out) while still dragging.
  3. Try to edit the spinbox.

Result: The spinbox cannot be edited anymore.

Expected Result: The spinbox should be editable.

I have also attached a clean project reproducing the bug (steps 1-5).


Thank you for the report. I was able to easily reproduce this issue in 4.16.3, 4.17.2, and 4.18.1. I have logged the issue, which you can follow if you’d like, here: Unreal Engine Issues and Bug Tracker (UE-52802)

If there is anything else that I can help you with please let me know.

All the Best,