Duplicating/copy-pasting a Button device corrupts its Timeline component and crashes the editor (reproducible EXCEPTION_ACCESS_VIOLATION)

Summary

Cloning a Button device (Device_Button_V2) in a UEFN level — via Ctrl+D (Duplicate) or copy-paste — produces a corrupted copy whose Timeline component is missing its update/finished delegate functions (EmissiveColorLerpTL, PulseColorTL, “Visualization Scale”). Loading or touching that corrupted actor later triggers a handled ensure (OverriddenPropertySet.cpp scope mismatch) followed by a reproducible EXCEPTION_ACCESS_VIOLATION crash of the editor. Seen twice in the same session at the identical crash address.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Stability

Steps to Reproduce

  1. Place a Button device (Device_Button_V2) in a UEFN level.
  2. Clone it — either with Ctrl+D (Duplicate) or copy-paste (Ctrl+C / Ctrl+V) — and move/transform the copy.
  3. Save the level.
  4. Reload the project (or just reopen the level) and interact with the level (e.g. save again, or assign the cloned button to a component reference field).

Expected result: a fully functional cloned button with intact Timeline delegate bindings.

Actual result: on every load of the cloned actor, the log shows:
Warning: While importing text for property ‘TimelinePostUpdateFunc’ in ‘Timeline’:
Unable to find function …/Device_Button_V2_C_UAID_…EmissiveColorLerpTL__UpdateFunc
Unable to find function …/Device_Button_V2_C_UAID_…PulseColorTL__UpdateFunc
Unable to find function …/Device_Button_V2_C_UAID_…Visualization Scale__UpdateFunc

Shortly before the crash we also saw a handled ensure:
Ensure condition failed: OverriddenProperties->GetOwner() == Owner
Incorrect owner passed. Scopes are mismatching!
[File: Engine/Source/Runtime/CoreUObject/Private/UObject/OverriddenPropertySet.cpp, Line: 195]

followed by:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000001c9b69e

The same crash address (0x…1c9b69e) recurred twice in the same session when touching the cloned button actor.

Engine version: 6.0.0-58011042 (++Fortnite+Release-42.20)

Workaround: avoid cloning Button devices — place fresh instances from the device palette instead.

Expected Result

Cloning a Button device should produce a fully working copy with intact Timeline delegate bindings, not a silently-corrupted actor that logs “Unable to find function” warnings and eventually crashes the editor with EXCEPTION_ACCESS_VIOLATION.

Observed Result

Log shows repeated “Unable to find function” warnings for the Timeline component of the cloned Button device (EmissiveColorLerpTL__UpdateFunc, PulseColorTL__UpdateFunc, “Visualization Scale”__UpdateFunc). Shortly before crashing, a handled ensure fires: “OverriddenProperties->GetOwner() == Owner — Incorrect owner passed. Scopes are mismatching!” (OverriddenPropertySet.cpp, line 195). The editor then crashes with Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000001c9b69e. Same address recurred twice in one session.

Platform(s)

Windows (UEFN editor, Engine 6.0.0-58011042 / ++Fortnite+Release-42.20)

Additional Notes

This is highly disruptive: it has crashed our session repeatedly (3+ times) whenever we touch a cloned Button device — including immediately after a plain Ctrl+C/Ctrl+V. It is effectively blocking work in a level that uses several placed Button devices.

FORT-1155433 has been created and its status is ‘Unconfirmed’. This is now in a queue to be reproduced and confirmed.

Update: this is broader than Button devices / cloning specifically. We’ve now hit the exact same crash (same ensure, same signature) from an Import operation as well, with no duplication or copy-paste involved. Combined with the related report at Error: Incorrect owner passed. Scopes are mismatching! (triggered by Alt-drag duplicating a plain Prefab Entity, no Button device involved), the common factor looks like the generic OverriddenPropertySet owner/scope handling whenever an actor/entity carrying overridden-property data gets attached to a new owner — via duplicate, copy-paste, or import. Button devices were just the easiest case for us to reproduce reliably, not the root cause.

Second update: we tried rebuilding our entities from scratch (fresh, non-cloned instances created via script from a Prefab class, no copy/paste/duplicate/import involved) to work around this. The crash STILL happens, same exact address (0x0000000001c9b69e), the moment we manually assign an actor reference (a button_device) to a custom Verse component’s field (e.g. a ?button_device property on an entity component) through the Details panel picker. So this isn’t limited to cloning/import at all — it looks like assigning an actor-ref value to a Verse-component field via the editor UI is broken outright in this build, regardless of how the owning entity/actor was created. This makes any Verse component with an actor/device-reference field effectively unusable through the normal Details panel workflow right now.