Summary
Since the 43.00 update, the Fortnite client crashes with the same error in almost every UEFN playtest session of my island. It has crashed 61 times since November 1, 2026, always with EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000020. None of my earlier crash reports (42.40 and older) have this error. Each time, the last thing in the client log is the client creating custom NPC pawns (CR_BP_CustomNPC_Pawn_C) and their Scene Graph entity components.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Stability
Steps to Reproduce
Steps to reproduce
Open the project in UEFN and Launch Session. Always works the first session. Make changes and push for a new session.
Play normally. The island has many NPC Spawner / Character-device NPCs with Verse npc_behaviors, persona (AI conversation) components and Scene Graph prefabs. NPCs begin loading into the map.
The client crashes after about 12 to 60 minutes (719 s to 3,486 s since start in most reports).
Expected Result
The session keeps running.
Observed Result
Client closes with:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x0000000000000020
The UEFN editor stays open. Typically, the last client log lines before the crash are:
LogActorEntityComponent: Verbose: CLIENT: Creating entitycomponent of type /EntityFramework/Verse/VNI/Entity.transform_component for object CR_BP_CustomNPC_Pawn_C…
LogActorEntityComponent: Verbose: CLIENT: Creating entitycomponent of type /VerseFortnite/Verse/VNI/VerseFortnite.Characters_fort_character_component for object CR_BP_CustomNPC_Pawn_C…
LogActorEntityComponent: Verbose: CLIENT: adopting replicated root Entity Custom_Player_Prefab_Entity_C_… for Owner CR_BP_CustomNPC_Pawn_C_…
LogCreativeAI: Warning: [3c4d] Was not able to assign this NPC has no NavSys! Invoker=FortAutoDetectNavInvokerClass_C
LogFortCosmetics: Display: [331a] CustomPlayerComponent not found for Pawn (CR_BP_CustomNPC_Pawn_C_…), skipping customization as potential part alterations require it.
LogAbilitySystem: Warning: CR_BP_CustomNPC_Pawn_C_…AbilityAsync_WaitGameplayTagCountChanged…: AbilitySystemComponent is nullptr! Could not register for gameplay tag event
LogCosmeticParts: [3daf] Loading UCosmeticMorphAdjustmentData data without checking if dependant part(s) are present.
21 of the last 22 crash logs end in this NPC pawn setup. The 22nd has no log.
Frequency
Nearly every session: 61 crashes from 2026-11-01 to 2026-11-09, up to 4 a day.
Crash report IDs (most recent first)
UECC-Windows-57A7A2C549639075E52A189A04091C17 (2026-11-09)
UECC-Windows-1215E5304F993736BBA542BA760D542A (2026-11-09)
UECC-Windows-FC2CC41946302D779B2A5EAA3E3FB825 (2026-11-09)
UECC-Windows-50CEB6474E331476C402099E75AC59D0 (2026-11-09)
UECC-Windows-23F6963D4D9EFB553FF4AEB436B0507C (2026-11-08)
Platform(s)
Windows/ UEFN when loading a session.
Windows 11 25H2 (10.0.26200)
Intel Core i5-14500, 64 GB RAM
NVIDIA GeForce RTX 4070
Additional Notes
The first crash with this address was the first session on 43.00 (2026-11-01). Before that, the island ran on 42.40 without it.
Minidumps and full client logs are available. I can send them privately.