Immediate crash in multiprocess PIE

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1

I’m working on map changes. This requires 2 game windows to test to make sure clients can transfer. I also unchecked “Use Single Process” in editor Play settings, as source states that PIE does not support seamless travel in single process mode.

After unchecking that, PIE does not start properly. Clicking the ‘Play’ button with “Number of Players: 2” immediately opens a new window, but it remains a black screen and never loads. title of window also describes it as “Client -2” (Single-process windows describe themselves as “Client 1” and “Server”).

A second window opens shortly after; it’s a 640x480 window (resolution in editor Play settings for 2nd process). This window promptly crashes, bringing up windows error report (“Looking for a solution online”, that one). I have gotten this window to load occasionally, but 90% of time it just crashes. I don’t know what, if anything, is different in rare instances where it does work.

There’s no error output at any point in this. However, the “Launch” button also crashes immediately, but this does give an error output. I don’t know if it’s unrelated, however.

most relevant lines from Launch crash are below. I’ve tried googling the “Metadata mismatch” warning but all other occurrences seem to be unrelated to my issue.

LogStats:Warning: MetaData mismatch. Did you assign a stat to two groups? New //STATGROUP_Threads//FLauncherTask///Thread_1afc_0///####STATCAT_Advanced#### old //STATGROUP_Threads//FLauncherTask///Thread_830_0///####STATCAT_Advanced####
LogPlayLevel: hax: LogModuleManager:Warning: ModuleManager: Module 'HTTPChunkInstaller' not found - its StaticallyLinkedModuleInitializers function is null.
LogPlayLevel: hax: LogInit:Display: RandInit(1730684034) SRandInit(1730684034).LogConsoleManager:Warning: Console variable 'r.MSAA.CompositingSampleCount' wasn't set ('Scalability' has a lower priority than 'ProjectSetting')
LogPlayLevel: hax:
LogPlayLevel: hax: [2015.10.07-23.53.32:671][  0]LogConsoleManager:Warning: Console variable 'r.MSAA.CompositingSampleCount' wasn't set ('Scalability' has a lower priority than 'ProjectSetting')LogModuleManager:Warning: ModuleManager: Module 'GameplayDebugger' not found - its StaticallyLinkedModuleInitializers function is null.
LogPlayLevel: hax:
LogPlayLevel: hax: [2015.10.07-23.53.36:349][  0]LogModuleManager:Warning: ModuleManager: Module 'GameplayDebugger' not found - its StaticallyLinkedModuleInitializers function is null.LogSlate:Warning: Failed to load font data from 'Arial'
LogPlayLevel: hax:
LogPlayLevel: hax: [2015.10.07-23.53.36:381][  0]LogSlate:Warning: Failed to load font data from 'Arial'LogInit:Display: Game Engine Initialized.
LogPlayLevel: hax:
LogPlayLevel: BuildCommand.Execute: ERROR: BUILD FAILED
LogPlayLevel: Program.Main: ERROR: AutomationTool terminated with exception:
LogPlayLevel: Program.Main: ERROR: Exception in AutomationScripts.Automation: Client exited with error code: -1073741819
LogPlayLevel: Stacktrace:    at Project.RunStandaloneClient(List`1 DeployContextList, String ClientLogFile, ERunOptions ClientRunFlags, String ClientApp, String ClientCmdLine, ProjectParams Params)
LogPlayLevel:    at Project.RunInternal(ProjectParams Params, String ServerLogFile, String ClientLogFile)
LogPlayLevel:    at Project.Run(ProjectParams Params)
LogPlayLevel:    at BuildCookRun.DoBuildCookRun(ProjectParams Params)
LogPlayLevel:    at BuildCommand.Execute()
LogPlayLevel:    at AutomationTool.Automation.Execute(List`1 CommandsToExecute, CaselessDictionary`1 Commands)
LogPlayLevel:    at AutomationTool.Automation.Process(String[] CommandLine)
LogPlayLevel:    at AutomationTool.Program.MainProc(Object Param)
LogPlayLevel:    at AutomationTool.InternalUtils.RunSingleInstance(Action`1 Main, Object Param)
LogPlayLevel:    at AutomationTool.Program.Main()
LogPlayLevel: ProcessManager.KillAll: Trying to kill 0 spawned processes.
LogPlayLevel: Program.Main: AutomationTool exiting with ExitCode=Error_Unknown
LogPlayLevel: Domain_ProcessExit
LogPlayLevel: copying UAT log files...
LogPlayLevel: RunUAT.bat ERROR: AutomationTool was unable to run successfully.
LogPlayLevel: Completed Launch On Stage: Run Task, Time: 8.750366
LogPlayLevel: BUILD FAILED
PackagingResults:Error: Error Launch failed! Unknown Error

To emphasize, single process PIE works fine. It’s just multi-process PIE and Launch that do not. I don’t know why UHT is crashing in this situation, as it appears to work just fine everywhere else.

2

Hi ,

I haven’t had this problem occur in 4.9 here. I tried with Use Single Process disabled and both Play As Client and Play As Listen Server for Editor Multiplayer Mode. I also had no problem opening Launch with Use Single Process disabled (though two shouldn’t be connected).

Are you able to reproduce this behavior in a new project, or only your current project? Can you take a screenshot of your Multiplayer Options settings in Editor Preferences so I can make sure I’m duplicating your setup? I’d also like to take a look at logs from project. If you can reproduce this in a new project, please let me see those logs (\Saved\Logs in project folder), otherwise let me see ones in your current project. Don’t do anything else during PIE, just reproduce problem, quit editor, and then send me logs. Make sure you’re giving it a few moments to attempt to open second window. Thanks!

3

I created a new project off First Person Template and tried 2 player multi-process Join As Client. That worked, although I did notice that first window was also “Client -2”, so that’s probably innocuous.

Trying on my current project still crashes.

Here are two log files generated. _2 log file cuts off suddenly, and I didn’t see anything particularly helpful in first one.

What I did to obtain these:

Started debugging in Visual Studio (already running), set to DebugGame Editor. Clicked ‘Play’; settings were already for Multiprocess, 2 clients. First window popped up immediately, followed by 2nd. 2nd window crashed after a few seconds. I allowed Windows to finish “Searching for solutions” before clicking “Close Program”. first window was still black, so I closed it by pressing X. Then I closed editor entirely.

4

Does this occur with both Play As Client and Play as Listen Server? Are you running with a vanilla version of engine, or have you added any Plugins or edited Source at all?

It may be helpful for me to look at project here. If you’d like, you can it up and upload it someplace like Google Drive or Dropbox, and send me a download link via PM on forums:

5

I have not modified source at all; no plugins or anything, no self changes. Just what Epic games launcher gives me when I update through there.

Play as Listen server did give a slightly different result. Instead of being black for duration, first window actually loaded game. 2nd window opened, joined server, and then promptly crashed. It appeared as a visible client in first window briefly before disappearing on crash.

I included logs folder in project rar. There are a large number of blueprint warnings in there due to animation blueprint attempting to access a pendingkill object. I assume this was caused by improper disconnect of client process.

6

Hey ,

Which version of editor are you using for this? I attempted to open in 4.9.2 and it gave me some errors.

7

4.9.2. I may have missed some files, since I’m not too used to zipping up my project. But I have no idea which, if any, I missed.

8

It should just be project folder in its entirety. So when you made this project, you created a new C++ project through Launcher? Did it start as 4.9.2 or was it upgraded from a previous version? I’ll keep trying to work with what you’ve given me, but I’m afraid any changes I make will run into different issues.

9

Upgraded to 4.9.2 recently. I can’t recall what I started as, probably around 4.7. issue occurred in 4.9.1 and I upgraded shortly after making this thread, in case it fixed issue (it didn’t). I can’t say if it occurred on any version earlier than 4.9.1 as that is when I first attempted multiprocess PIE.

10

Okay, I’m getting a crash in your project whether Use Single Process is enabled or not, but they’re two different crashes. In both cases (if editor itself crashes), a Crash Reporter window appears. Are you getting this as well? If so, can you give me information from window, including Machine ID, and paste it here? I’d like to make sure we’re seeing same thing.

11

I don’t believe so. As I mentioned in first post, ‘Launch’ does crash, and does give me an output log, which I included in first post.

Play in Editor does work fine and launches game, as long as “Single process” is checked. This works with both 1 client and multiple.

I’m not experiencing any crashes of entire editor. Only game window(s) that open when trying to launch game.

12

You might need to take a copy of your project and remove pieces one by one, to see if this is asset related. When I removed some of actors you had added to Example_Map, I was able to run with Use Single Process disabled without crashing. I believe they were shotgun assets. call stack I’m seeing from crashes I witnessed appear to be related to actor replication.

I’ll investigate further to see what specifically about these actors are causing problem, but I wanted to let you know so you can continue testing around them, if possible. It might be worth reconstructing these blueprints and using those instead, to see if that also causes crash.

13

Okay, it appears this may involve some corrupted Blueprints. I started removing assets from map, and when I had removed either both ShotgunBlueprint instances or haxDummy instance, game stopped crashing. I then added a new instance of Actor I had removed, and it also did not crash.

Please give this a try and let me know what happens. As I mentioned, what happens in my version of your project does not seem to happen in yours, but call stack was indicating a charactermovement component replication issue, and I believe it may have simply been some corrupted instances in map.

14

That did it. Got rid of dummy entirely since I don’t actually need it anymore, and re-placed shotgun. Interestingly, at one upgrade I did get warnings about dummy’s character movement, and re-created blueprint then.

Thanks.

15

Okay, no, it’s doing it again. I think it started crashing again when I first pressed compile C++ editor button, but that could be a coincidence.

dummy is still completely deleted. I also deleted shotgun blueprint and re-created it using default values after it started crashing again. Multiprocess PIE was working for a while, but then it suddenly started crashing again. I did not re-add shotgun blueprints to map.

It’s crashing most of time with “Play as Listen Server” selected. “Play as Client” works, but since that puts server in new process, I can’t use breakpoints to see why servertravel isn’t working.

16

That would indicate it’s a code problem. I hot compiled as well and started having same problem again. I’m going to get one of our more code knowledgeable guys to look into it.

I’d also warn you that disabling Use Single Process is not recommended by devs (there’s been some talk of removing option from editor altogether). I’d imagine that using a breakpoint to detect server travel won’t be as useful as watching your logs on both client and server for that.

17

i would like to add, that i experience same issue:
Disabling single process like:

933×221 15.4 KB

This Results in both clients to start, but when trying to host a local game through Sessions, both clients crash immediatly, this is related Log:

1348×204 16.6 KB

Using single process works fine, but prevents me from using seamless travel :confused:

18

Hey StreakyCat-

What exactly do you mean by “host a local game through Sessions”? As you mentioned, unchecking Use Single Process checkbox will spawn both players in a clean project. Could you post your process for setting up your seamless travel so that I can follow same process for testing on my end?

19

Hey and StreakyCat-

I’ve not heard back from you in a few days and do not have any further leads to test at moment. If there is any additional information you can provide about how your projects are setup that would help me reproduce crash on my end please let me know in a comment. If possible, posting a sample project with crash occurring along with how project was created/setup would be helpful as well .

Cheers

20

I’ve sent a copy of my project via forum PM, and it crashes for him, although not in same ways. Beyond that, I don’t have anything to add. It just sounds like ideal solution for me would be if single process seamless travel worked, esp since there are other known issues with multi-process.

With that said, I have a basic menu now, so I don’t need PIE for travel testing; it’s just more convenient. It’s irksome that it crashes, but it’s no longer a pressing issue for me.