Adding a breakpoint to a blueprint node connected to the "Event Tick" constrains the user's mouse cursor to the blueprint window when clicking the "Play" button

Steps to reproduce:

  1. Start UE4.
  2. Create a simple Blueprint, connected to the “Event Tick” node (Note: The issue doesn’t reproduce using the “Event BeginPlay” node).
  3. Right click any of the nodes along the path that have execution pins, and choose “Toggle breakpoint (F9)” or “Add breakpoint”.
  4. Return to the scene viewport tab.
  5. Press the Play button.
  6. Try to click any of the buttons on the main toolbar (e.g. “Find Node”, “Step Into”, “Stop”, etc).

Current behaviour:

The user’s mouse cursor gets trapped within the confines of the blueprint window (albeit with a thicker, invisible border at the bottom). Please see the attached video: [link]

The user can’t even reach the “Stop” button at the top. Note: The user can exit by pressing the Escape key on the keyboard or Shift+F1.

Using UE4.17.2.

Expected behaviour:

Same as when connecting it to the “Event BeginPlay” node, the mouse cursor should not be constrained.

Hello Andrei,

Thank you for the report. Fortunately, I was able to reproduce the issue in 4.16, 4.17, and 4.18 Preview thanks to your helpful video. I have successfully logged the issue. If you would like to track it please feel free to follow this link: Unreal Engine Issues and Bug Tracker (UE-50619)

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

Best Regards,


if it helps, seems that the error only occurs when you have pinned the blueprints window to the editor. so for now a workaround is to detach the blueprints windows.