Summary
“OnMouseButtonDown” override in a Widget Blueprint returns nothing on M1 macs. I haven’t tested every override, but so far I have no ability to register mouse clicks or hovers when I create a Widget BP, add it to the viewport, enable UI-only input and set Show Mouse Cursor = True. The OnMouseButtonDown override is set to “Handled”.
This bug occurs on a Mac M1 laptop and iMac. It doesn’t occur on a M2 laptop or a Windows 11 PC. I haven’t been able to test on any other Mac systems. It only occurs with Unreal 5.8 because a 5.7 build works fine on all systems.
What Type of Bug are you experiencing?
Gameplay
Steps to Reproduce
1 - In a new project make a blank level and Widget Blueprint
2 - In the WBP add a canvas and text box, set the root node to be visible (so it receives mouse input).
3 - Go to the WBP graph and add an override for OnMouseButtonDown. Connect it to a Print String that should print when the mouse button is triggered. Set the Return Value = Handled.
4 - in the blank level’s level BP add code to do the following…create a Widget BP, add it to the viewport, enable UI-only input and set Show Mouse Cursor = True.
5 - set the level’s GameMode to GameModeBase
Expected Result
OnMouseButtonDown should trigger the print string.
Observed Result
Nothing is triggered on M1 Macs.
Affects Versions
5.8
Platform(s)
Mac
Windows