Summary
Since updating to v42.00, running Launch Memory Calculation on my island crashes the Fortnite client at the final stage. The same crash happens on End Game. Because the client crashes before the calculation completes, the private version stays at “Memory Usage - Action Needed” and I cannot publish an update.
Build: ++Fortnite+Release-42.00-CL-56878558
Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff
7 crash reports so far. All 7 have the same PCallStackHash (B975EC5D0C908E9421FC908BC4BBF3F3BD22D7FC) and all 7 have <IsPhysicsEnabled>true</IsPhysicsEnabled> in the crash context. MemoryStats.bIsOOM = 0 on all 7 (64 GB machine).
The memory calculation completed normally for this island on 41.30 (26,251 / 100,000).
Logs from the crashing run, and from a run on a new empty project that did not crash, are in Additional Notes.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Memory Calculation
Steps to Reproduce
- Open a UEFN project on v42.00 with Physics enabled (Project > Project Settings > Experimental/Beta Access > Physics).
- Launch a session and join it.
- Project menu > Launch Memory Calculation.
- Wait for the on-screen status to reach “Finished cooking for all connected platforms. Freezing players while we load your project.”
- The Fortnite client crashes about 1.7 seconds after that message appears.
The same crash happens when using End Game.
I also ran these steps on a new empty project with Physics enabled. That run did not crash and the calculation completed (2,454 / 100,000). Logs from both runs are in Additional Notes.
Expected Result
The memory calculation completes, the result is reported in-client, and the private version’s “Memory Usage” validation check passes so the island can be published.
Observed Result
The Fortnite client crashes with:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff
The memory calculation never completes, and the private version stays at “Memory Usage - Action Needed”, which blocks publishing.
The last log lines before the client dies, identical on all 7 crashes:
Finished cooking for all connected platforms. Freezing players while we load your project.
LogFortPlayerStasis: Applied Stasis Mode [3] to [<player>]
LogChaosMover: Warning: Attempted to queue an unregistered movement mode: Stasis
on owner PlayerPawn_Newton_C_2147482646
LogWorldPartition: UWorldPartition::Uninitialize : World = <island>
LogChaosMover: Warning: ChaosCharacterWalkingSource requires
FChaosMoverSimulationDefaultInputs and FCharacterDefaultInputs
LogChaosMover: Warning: UChaosCharacterWalkingExecutor (WalkingExecutor):
Requires FChaosMoverSimulationDefaultInputs and FCharacterDefaultInputs
... those two lines repeat every tick, 39 times over 1.546 s ...
*** log ends here, process died - no Fatal line was written ***
Platform(s)
Windows (Win64) - Windows 11, 64 GB RAM
Island Code
4471-5708-8314
Additional Notes
CRASH LIST
2026-08-20 07:38 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
2026-08-20 09:42 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
2026-08-20 09:47 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
2026-08-20 10:30 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
2026-08-22 08:44 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
2026-08-22 08:58 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
2026-08-22 09:13 42.00-CL-56878558 B975EC5D0C90 IsPhysicsEnabled=true ACCESS_VIOLATION
CRASH GUIDs (all submitted via the in-client crash reporter)
UECC-Windows-80A7EE404C6F0F4F6E9ED6A940E8B244_0000 2026-08-22 09:13
UECC-Windows-CA7761A746C9329C5429F7B1F4490ED2_0000 2026-08-22 08:58
UECC-Windows-E873A84840B61C02A12FDB849609D7AA_0000 2026-08-22 08:44
UECC-Windows-9B0F3FC3434199379470FFAEB70344B7_0000 2026-08-20 07:38
UECC-Windows-179962464020743ED055D8B2AEB97DB9_0000 2026-08-20 09:42
UECC-Windows-7706B2E549DC8B8AB4A1D08D7A3348F2_0000 2026-08-20 09:47
UECC-Windows-3CDF802140EB1A36B887EF887FE32025_0000 2026-08-20 10:30
MEMORY CALCULATION RESULTS ON RECORD
2026-08-18 my island 32,989 / 100,000 (on 41.30)
2026-08-19 my island 26,251 / 100,000 (on 41.30)
2026-08-22 new project 2,454 / 100,000 (empty test project, physics on, 42.00)
Download size is 258.87 MB / 400 MB. Since updating to 42.00 the calculation has not completed on my island, so I have no newer reading for it.
CLIENT LOG - crashing run
FortniteGame.log from UECC-Windows-80A7EE404C6F0F4F6E9ED6A940E8B244_0000
[2026.08.22-14.13.11:360] LogGlobalStatus: ... Completed cook for request project
0b27ab2e-4bb7-901d-0413-43b7a6ef14b6 root
a3c55b2a-447c-f9a3-ac0c-76a124e19649@74
{EConsumerRole::Client - Windows}, cook was a success.
[2026.08.22-14.13.27:813] LogGlobalStatus: ... Completed cook ... {EConsumerRole::Server - Linux},
cook was a success.
[2026.08.22-14.13.27:819] LogGlobalStatus: ... Finished cooking for all connected platforms.
Freezing players while we load your project.
[2026.08.22-14.13.27:825] LogFortControllerComponent_MemorySampler: Memory Sampler Entering New
State : Idle
[2026.08.22-14.13.27:865] LogFortPlayerStasis: [3cb5] Applied Stasis Mode [3] to [RiptideRip]
[2026.08.22-14.13.27:865] LogFortPlayerStasis: [3cb5] Applied Stasis Mode [3] to [RiptideRip]
[2026.08.22-14.13.27:877] LogChaosMover: Warning: Attempted to queue an unregistered movement
mode: Stasis on owner PlayerPawn_Newton_C_2147482646
[2026.08.22-14.13.27:959] LogWorldPartition: UWorldPartition::Uninitialize : World =
/a3c55b2a-447c-f9a3-ac0c-76a124e19649/StealAnEgg_LevelInstance_1.StealAnEgg
[2026.08.22-14.13.28:191] FortLogMinigameSettingsBuilding: AFortMinigameSettingsBuilding::EndPlay:
FullName[Device_ExperienceSettings_V2_UEFN_C ...], EndPlayReason[3]
[2026.08.22-14.13.28:...] LogChaosMover: Warning: ChaosCharacterWalkingSource requires
FChaosMoverSimulationDefaultInputs and FCharacterDefaultInputs
[2026.08.22-14.13.28:...] LogChaosMover: Warning: UChaosCharacterWalkingExecutor (WalkingExecutor):
Requires FChaosMoverSimulationDefaultInputs and FCharacterDefaultInputs
... those two lines repeat every tick, 39 times ...
[2026.08.22-14.13.29:505] LogChaosMover: Warning: ChaosCharacterWalkingSource requires
FChaosMoverSimulationDefaultInputs and FCharacterDefaultInputs
*** log ends here, process died ***
*** Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff ***
CLIENT LOG - run on the new empty project, which did not crash
[2026.08.22-14.27.39:132] LogFortControllerComponent_MemorySampler: Memory Sampler Entering New
State : Idle
[2026.08.22-14.27.39:211] LogFortPlayerStasis: [3cb5] Applied Stasis Mode [3] to [RiptideRip]
[2026.08.22-14.27.39:222] LogChaosMover: Warning: Attempted to queue an unregistered movement
mode: Stasis on owner PlayerPawn_Newton_C_2147482646
[2026.08.22-14.27.39:248] LogChaosMover: Warning: ChaosCharacterWalkingSource requires ...
[2026.08.22-14.27.39:253] LogWorldPartition: UWorldPartition::Uninitialize : World =
/82ac4280-9893-4472-bbb8-fcacb5d32f4d/PhysicsTest_LevelInstance_2.PhysicsTest
[2026.08.22-14.27.39:284] LogChaosMover: Warning: ChaosCharacterWalkingSource requires ...
[2026.08.22-14.27.39:313] LogChaosMover: Warning: ChaosCharacterWalkingSource requires ...
[2026.08.22-14.27.39:517] LogGlobalStatus: ... Finished cooking for all connected platforms.
Freezing players while we load your project.
[2026.08.22-14.27.43:038] Memory Sampler Entering New State : Ready
[2026.08.22-14.27.43:571] Memory Sampler Entering New State : Initializing
[2026.08.22-14.27.43:640] Memory Sampler Entering New State : InProgress
[2026.08.22-14.27.46:509] Memory Sampler Entering New State : Ready
UEFN EDITOR LOG - crashing run (UnrealEditorFortnite.log)
The editor requests the project size, the sampler goes to Idle, and then nothing further arrives. 30 seconds later the editor’s Valkyrie beacon connection to the session times out, and the reconnect attempt also times out.
[2026.08.22-14.12.00:033] LogValkyrie: ProjectSizeRequest::GetProjectUploadSize for module
a3c55b2a-447c-f9a3-ac0c-76a124e19649
(FlowId=<none>, ResolutionId=58a279f0-2e27-5400-90fb-dcf41cf03b6a)
[2026.08.22-14.13.15:127] LogValkyrie: ProjectSizeRequest::GetProjectCookedSize for module
a3c55b2a-447c-f9a3-ac0c-76a124e19649
[2026.08.22-14.13.15:911] LogValkyrie: ProjectSizeRequest::Completed for module
a3c55b2a-447c-f9a3-ac0c-76a124e19649 (FlowId=<none>)
[2026.08.22-14.13.27:825] LogValkyrieBeacon: [3902] (ValkyrieBeaconClient_4) MinigameStateChanged:
EFortMinigameState::PreGame
[2026.08.22-14.13.27:825] LogValkyrieBeacon: [3975] (ValkyrieBeaconClient_4)
SpatialGameplayActorLoadingStateUpdated:
ESpatialLoadingState::Initializing
[2026.08.22-14.13.27:825] LogValkyrieBeacon: MemorySamplerStateChanged:
EMemorySamplerState::Idle
(client crashes here at 14:13:29 - nothing further is received by the editor)
[2026.08.22-14.13.58:892] LogNet: Warning: UNetConnection::Tick: Connection TIMED OUT. Closing
connection.. Elapsed: 30.01, Real: 30.01, Good: 30.01,
DriverTime: 274.72, Threshold: 30.00, [UNetConnection]
RemoteAddr: 18.88.2.32:15008, Name: IpConnection_4,
Driver: Name:IpNetDriver_4 Def:BeaconNetDriver IpNetDriver_4,
IsServer: NO, PC: NULL, Owner: ValkyrieBeaconClient_4
[2026.08.22-14.13.58:892] LogNet: Error: UEngine::BroadcastNetworkFailure:
FailureType = ConnectionTimeout,
ErrorString = UNetConnection::Tick: Connection TIMED OUT.
Closing connection.. (same connection as above)
[2026.08.22-14.13.58:892] LogValkyrieBeacon: [3ea6] (ValkyrieBeaconClient_4)
AValkyrieBeaconClient::OnFailure - We have registered a failure
in the Valkyrie beacon.
[2026.08.22-14.13.58:893] LogBeacon: OnlineBeacon ValkyrieBeaconClient_4 requesting net driver
destruction: Name:IpNetDriver_4 Def:BeaconNetDriver IpNetDriver_4
[2026.08.22-14.13.58:893] LogValkyrieRequestManagerEditor: Warning: Encountered Network Error:
UNetConnection::Tick: Connection TIMED OUT. Closing connection..
[2026.08.22-14.13.58:893] LogNet: UNetConnection::Close: ... Result=ConnectionTimeout,
ErrorContext="ConnectionTimeout"
[2026.08.22-14.13.58:900] LogValkyrieRequestManagerEditor:
HandleValkyrieBeaconConnectionFailureAfterConnected -
ConnectionStatus: 3
[2026.08.22-14.13.58:900] LogValkyrieRequestManagerEditor: CleanupAfterServerConnectionLost -
initiating reconnection flow
[2026.08.22-14.13.58:900] LogValkyrieRequestManagerEditor: Executing Step DestroyValkyrieBeacon
[2026.08.22-14.13.58:900] LogValkyrieSummary: Destroying Valkyrie Beacon
[2026.08.22-14.13.59:002] LogValkyrieRequestManagerEditor: Attempting beacon reconnect.
Attempt number: 1
[2026.08.22-14.13.59:142] LogValkyrieActivityTracker: Session -> Start Activity: ConnectToBeacon -
Connecting to beacon
[2026.08.22-14.14.59:151] LogNet: Warning: UNetConnection::Tick: Connection TIMED OUT. Closing
connection.. Elapsed: 60.16, Real: 60.01, Good: 60.01,
DriverTime: 60.16, Threshold: 60.00, RemoteAddr: 18.88.2.32:15008,
Name: IpConnection_5, Owner: NULL
[2026.08.22-14.14.59:152] LogNet: Error: UEngine::BroadcastNetworkFailure:
FailureType = ConnectionTimeout
[2026.08.22-14.14.59:152] LogValkyrieBeacon: [3ea6] (ValkyrieBeaconClient_5)
AValkyrieBeaconClient::OnFailure - We have registered a failure
in the Valkyrie beacon.
[2026.08.22-14.14.59:159] LogValkyrieActivityTracker: Warning: Session -> Fail Activity:
ConnectToBeacon - Failed to connect to beacon
UEFN EDITOR LOG - run on the new empty project, which did not crash
[2026.08.22-14.27.39:132] LogValkyrieBeacon: MemorySamplerStateChanged: Idle
[2026.08.22-14.27.42:045] LogValkyrieSummary: Server Summary - Successfully activated content on
all platforms
[2026.08.22-14.27.43:056] LogValkyrieBeacon: MemorySamplerStateChanged: Ready
[2026.08.22-14.27.43:557] LogValkyrieBeacon: MemorySamplerStateChanged: Initializing
[2026.08.22-14.27.43:646] LogValkyrieBeacon: MemorySamplerStateChanged: InProgress
[2026.08.22-14.27.46:719] MemoryTestResults: ------ Memory Calculation Results Summary ------
[2026.08.22-14.27.46:719] MemoryTestResults: Result: SUCCESS
[2026.08.22-14.27.46:719] MemoryTestResults: Duration: 2s
[2026.08.22-14.27.46:719] MemoryTestResults: Highest Memory Usage: 2,454 / 100,000
[2026.08.22-14.27.46:719] MemoryTestResults: Number of Locations Sampled: 1
[2026.08.22-14.27.46:720] LogValkyrieBeacon: MemorySamplerStateChanged: Ready
On the crashing run the memory sampler never moves past Idle, so no MemoryTestResults block is ever written and the editor loses the session.