Summary
In UE 5.8, dragging an asset into a project Content folder intermittently breaks the Content Drawer. The folder tree in the left-hand panel loses its folder icons and stops responding to the mouse, and the drop is rejected, so the asset cannot be copied. The rest of the editor stays responsive.
The bug only affects the Content Drawer. Docking it as a regular Content Browser clears the problem immediately, and so does restarting the editor.
What Type of Bug are you experiencing?
UI / Tools
Steps to Reproduce
in UE 5.8, So1. Open a project in UE 5.8.
2. In Content Browser settings, enable Show Engine Content and Show Plugin Content.
3. Open the Content Drawer (do not dock it).
4. Navigate to an Engine or Plugin content folder — e.g. Engine > Plugins > Water > Materials > WaterSurface.
5. Drag an asset into a folder under project Content.
6. Repeat over a normal work session. The failure appears intermittently.
metimes (not always) when dragging and dropping to copy assets from the
Expected Result
The drop is accepted and the Copy Here / Move Here / Advanced context menu appears.
Observed Result
The folder tree in the left-hand panel enters a broken state:
- Folder icons stop rendering. Folder names and the tree hierarchy still render correctly.
- The tree stops responding to the mouse entirely — no hover state, no highlight, no selection.
- The drag shows a rejected-drop cursor and releasing does nothing. No asset is copied.
Note that the tree is not cleared: the underlying data is still displayed. Only the icons and the mouse interaction are lost.
The drawer stays in this state until it is docked as a Content Browser or the editor is restarted.
Affects Versions
5.8
Platform(s)
Windows
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Additional Notes
Note on scope (unconfirmed)
The steps above are the case I have reproduced. However, I believe I have also hit this while dragging my own project assets within Content, with no Engine or Plugin content involved. I have not been able to confirm that, so please do not treat the Engine/Plugin source as a necessary condition.
-Frequency
Intermittent, 4 to 5 occurrences over two days of normal work.
-Workaround
Dock the Content Drawer as a standard Content Browser, or restart the editor.
-Environment
- Unreal Engine 5.8, [Launcher binary / source build]
- Windows 11
- Blueprint project
(Used AI for translation and organizing the report)