# Fatal Error crashes on servertravel

**URL:** <https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011>\
**Category:** Multiplayer & Networking\
**Tags:** Networking, fatal-error, servertravel, unreal-engine, crash, bug-report, question\
**Created:** [June 20, 2017, 6:13pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011 "2017-06-20T18:13:00Z")\
**Posts on this page:** 20\
**Page:** 1

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 20, 2017, 6:13pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/1 "2017-06-20T18:13:00Z")

</div>

In 4.16.1 there are a constant amount of unknown fatal error crashes that occur on servertravel.

```
[2017.06.20-17.57.33:751][91]LogWindows:Warning: CreateProc failed (2) ../../../Engine/Binaries/Win64/CrashReportClient.exe "H:/GAME/WindowsNoEditor/WindowsNoEditor/Game/Saved/Crashes/UE4CC-Windows-4C804C9F41BF70FD2E8273BEE08A4110_0000" -AppName=UE4-Game -CrashGUID=UE4CC-Windows-4C804C9F41BF70FD2E8273BEE08A4110_0000 -DebugSymbols=..\..\..\Engine\Intermediate\Symbols
[2017.06.20-17.57.33:751][91]LogWindows: Could not start CrashReportClient.exe
[2017.06.20-17.57.33:751][91]LogMemory: Platform Memory Stats for WindowsNoEditor
[2017.06.20-17.57.33:751][91]LogMemory: Process Physical Memory: 1117.67 MB used, 1118.00 MB peak
[2017.06.20-17.57.33:751][91]LogMemory: Process Virtual Memory: 2442.87 MB used, 3331.46 MB peak
[2017.06.20-17.57.33:751][91]LogMemory: Physical Memory: 8041.95 MB used, 16525.16 MB free, 24567.11 MB total
[2017.06.20-17.57.33:751][91]LogMemory: Virtual Memory: 3092.70 MB used, 16525.16 MB free, 8388608.00 MB total
[2017.06.20-17.57.33:751][91]LogThreadingWindows:Error: Runnable thread PoolThread 4 crashed.
[2017.06.20-17.57.33:751][91]LogWindows:Error: === Critical error: ===
[2017.06.20-17.57.33:751][91]LogWindows:Error: 
[2017.06.20-17.57.33:751][91]LogWindows:Error: Fatal error!
[2017.06.20-17.57.33:751][91]LogWindows:Error: 
[2017.06.20-17.57.33:751][91]LogWindows:Error: Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x00000030
[2017.06.20-17.57.33:751][91]LogWindows:Error: 

```

These crashes never occured in 4.15.2, and they are very inconsistent. Sometimes after starting the game on 2 separate machines, you can servertravel between 4-5 levels, and other times it will fatal crash on the very fist servertravel…

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 20, 2017, 9:46pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/2 "2017-06-20T21:46:32Z")

</div>

Exception thrown at 0x00000001410BADAB in Game-Win64-Shipping.exe: 0xC0000005: Access violation reading location 0x0000000100000030.

After debugging the crash in visual studio the crash seems to happen at this breakpoint:

```
void RequestIsComplete()
	{
		check(bRequestOutstanding);
		if (!bCanceled && Priority > AIOP_Precache)
		{
			GatherResults();
		}
		SetComplete();
		FScopeLock Lock(&FPakReadRequestEvent);
		bRequestOutstanding = false;
		if (WaitEvent)
		{
			WaitEvent->Trigger(); (<----BREAK POINT)
		}
	}

```

This function is in IPlatformFilePak.cpp

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 20, 2017, 11:28pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/3 "2017-06-20T23:28:11Z")

</div>

Since the crash seems related to \*.pak file loading/reading at servertravel, I tested to build and package the project with pak files disabled. This stops all crashes at servertravel, altho the resulting project build is twice the size and it is obviously not an acceptable solution that can be shipped…

---

<div class="post-metadata">

**Author:** ![Sean\_Flint](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Sean\_Flint](https://forums.unrealengine.com/u/Sean_Flint)\
**Post date:** [June 21, 2017, 7:32pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/4 "2017-06-21T19:32:21Z")

</div>

Hey MADHOUSE,

I gave this a shot in my test project, but I didn’t see any crashes occur in 4.16.1. Could you please provide the logs so I can take a look at those, as well as give this a shot in a clean project and let me know if you’re seeing it there too.

Thanks

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 21, 2017, 9:58pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/5 "2017-06-21T21:58:42Z")

</div>

I will investigate as much as I can, I suspect there might be a need to put larger amount of data into the pak to cause these issues. It could be usefull to have an engineer look at this section of code since this issue did not happen before 4.16. Someone with more insight into what has changed and why this would happen could perhaps shed more light on it.

On my end all I can do is process-of-elimination which might take a while to analyse.

---

<div class="post-metadata">

**Author:** ![nrossol](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@nrossol](https://forums.unrealengine.com/u/nrossol)\
**Post date:** [June 25, 2017, 5:16pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/6 "2017-06-25T17:16:19Z")

</div>

By any chance, are any of your Levels performing a Multicast call from inside a Level Blueprint? If so, it’s possible that’s it’s related to a confirmed 4.16 Engine bug I recently posted here:

> **[\[Bug-Critical\]\[Reproducible\] Any Level Blueprint Multicasts with any Params...](https://forums.unrealengine.com/questions/660195/bug-criticalreproducible-any-level-blueprint-multi.html)**
>
> Level Blueprints can no longer make any Multicast calls with any parameters in 4.16. Doing so will crash the engine in the following way: Steps to reproduce from Blank Project: 1: Create a new empty 4.16 project with 2 levels. Call them LevelA and...

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 25, 2017, 7:01pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/7 "2017-06-25T19:01:28Z")

</div>

Greetings. Hmm interesting, some of the levels are indeed using multicast RPC’s to reset states on level actors during match restarts, I’ll look into it this week and return with results, it could very well be the related to the same issue.

Thanks for the information!

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 28, 2017, 10:53pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/8 "2017-06-28T22:53:02Z")

</div>

Im still getting fatal error crashes. Debugging in visual studio still breaks at this function in IPlatformFilePak.cpp altho I haven’t seen more “Level was reloaded before it even closed the linker from a previous load.” crashes yet, so I cant tell if they are related. I have had quite a few of those in the past aswell.

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 28, 2017, 11:37pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/9 "2017-06-28T23:37:08Z")

</div>

![201733-fatalerrorcrash.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/a/71a1249ea99fb8361600c1527ff9ef4277f25e7a.jpeg)

Crash log: [[2017.06.28-23.29.06:847][238]LogPackageName: SearchForPackageOnDisk took 0.93 - Pastebin.com](https://pastebin.com/DpZqMi7m)

This issue is currently critical and shipping breaking.

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [June 29, 2017, 10:23pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/10 "2017-06-29T22:23:09Z")

</div>

and sometimes the crash provides less information then in the log above, but still relates to IPlatformFilePak.cpp :

> **[\[2017.06.29-22.17.51:946\]\[393\]LogPackageName: SearchForPackageOnDisk took ...](https://pastebin.com/dcd7NKFj)**
>
> Pastebin.com is the number one paste tool since 2002. Pastebin is a website where you can store text online for a set period of time.

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 2, 2017, 5:27pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/11 "2017-07-02T17:27:24Z")

</div>

These crashes still occur in 4.16.2…

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 4, 2017, 9:47pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/12 "2017-07-04T21:47:49Z")

</div>

Any news on this?

---

<div class="post-metadata">

**Author:** ![Sean\_Flint](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Sean\_Flint](https://forums.unrealengine.com/u/Sean_Flint)\
**Post date:** [July 5, 2017, 7:49pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/13 "2017-07-05T19:49:09Z")

</div>

Hey MADHOUSE,

I’ve reproduced a crash on Server Travel that was reported by nrossol, and entered that ticket here: [Unreal Engine Issues and Bug Tracker (UE-46854)](https://issues.unrealengine.com/issue/UE-46854)

If you’re seeing something different, I haven’t been able to reproduce that on my end, so unfortunately I can’t get a ticket in for that just yet. If you’re able to narrow it down and provide me with a repro case or a project I can use, I’d be glad to take another look at it.

Thanks

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 5, 2017, 8:54pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/14 "2017-07-05T20:54:39Z")

</div>

Greetings.  
I have also had problems with UE-46854, altho this is a different issue unfortunately. I’ll explore the issue some more this week and see If I can find any more information…

I’ll post back if I have any results. The issue is there obviously but it seems very very low-level and its difficult to debug on my end so it might take some time.

Best Regards

---

<div class="post-metadata">

**Author:** ![lennysunreal](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/lennysunreal/32/984341_2.png) [@lennysunreal](https://forums.unrealengine.com/u/lennysunreal)\
**Post date:** [July 20, 2017, 2:06am UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/15 "2017-07-20T02:06:14Z")

</div>

We got this one too or somthing similar maybe

[https://udn.unrealengine.com/questions/382428/package-crash-assertion-failed-iplatformfilepakcpp.html](https://udn.unrealengine.com/questions/382428/package-crash-assertion-failed-iplatformfilepakcpp.html)

---

<div class="post-metadata">

**Author:** ![Sean\_Flint](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Sean\_Flint](https://forums.unrealengine.com/u/Sean_Flint)\
**Post date:** [July 20, 2017, 5:34pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/16 "2017-07-20T17:34:00Z")

</div>

Thanks for the heads up, I’ve assigned your ticket out for investigation.

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 20, 2017, 8:43pm UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/17 "2017-07-20T20:43:01Z")

</div>

There is definitely something wierd going on there when the engine attempts to read or serialize content from the pak file. At the assertion break the WaitEvent / Trigger event reference/value is null, as well as almost all variables in that section.

```
         if (WaitEvent)
         {
             WaitEvent->Trigger();
         }

```

Resulting in crash:  
EXCEPTION\_ACCESS\_VIOLATION reading address 0xffffffff

Please post back if there is any progress on this issue. This problem is still shipping breaking.

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 25, 2017, 3:20am UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/18 "2017-07-25T03:20:22Z")

</div>

Sometimes this is the error crash details, and a bit different from the more usual crash log and messages:

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 25, 2017, 3:29am UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/19 "2017-07-25T03:29:25Z")

</div>

Error: Runnable thread TaskGraphThreadNP 1 crashed.  
=== Critical error: ===

```
Fatal error: [File:H:\UnrealEngine-release\Engine\Source\Runtime\Core\Private\Windows\WindowsPlatformMisc.cpp] [Line: 482] 
Pure virtual function being called

KERNELBASE.dll!0x00000000FD149E5D
Game.exe!FOutputDeviceWindowsError::Serialize() [h:\unrealengine-release\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:120]
Game.exe!FOutputDevice::Logf__VA() [h:\unrealengine-release\engine\source\runtime\core\private\misc\outputdevice.cpp:70]
Game.exe!FDebug::AssertFailed() [h:\unrealengine-release\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
VCRUNTIME140.dll!0x00000000EE5C4A74
Game.exe!FPakProcessedReadRequest::RequestIsComplete() [h:\unrealengine-release\engine\source\runtime\pakfile\private\iplatformfilepak.cpp:2740]
Game.exe!FPakAsyncReadFileHandle:oProcessing() [h:\unrealengine-release\engine\source\runtime\pakfile\private\iplatformfilepak.cpp:3079]
Game.exe!TGraphTask<FAsyncIOCPUWorkTask>::ExecuteTask() [h:\unrealengine-release\engine\source\runtime\core\public\async\taskgraphinterfaces.h:886]
Game.exe!FTaskThreadAnyThread::ProcessTasks() [h:\unrealengine-release\engine\source\runtime\core\private\async\taskgraph.cpp:1277]
Game.exe!FTaskThreadAnyThread::ProcessTasksUntilQuit() [h:\unrealengine-release\engine\source\runtime\core\private\async\taskgraph.cpp:1171]
Game.exe!FTaskThreadBase::Run() [h:\unrealengine-release\engine\source\runtime\core\private\async\taskgraph.cpp:643]
Game.exe!FRunnableThreadWin::Run() [h:\unrealengine-release\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:76]
Game.exe!FRunnableThreadWin::GuardedRun() [h:\unrealengine-release\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:33]
kernel32.dll!0x0000000076E9652D
ntdll.dll!0x00000000770CC541
ntdll.dll!0x00000000770CC541
```

---

<div class="post-metadata">

**Author:** ![MADHOUSE](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MADHOUSE](https://forums.unrealengine.com/u/MADHOUSE)\
**Post date:** [July 27, 2017, 3:19am UTC](https://forums.unrealengine.com/t/fatal-error-crashes-on-servertravel/399011/20 "2017-07-27T03:19:40Z")

</div>

This bug seems to be gone in 4.17 preview 3.

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