[Sample Project Included ~ Demo Recording] UE4 Permanently Hangs when run Demoplay from a BP console command

Development Programming & Scripting Blueprint
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1

Dear Epic,

#Issue

The only BP code in this project is this 1 picture, and it still causes the hang, in a BP only project

Test is a valid replay file that loads fine if I use the console directly. But if I try to use this console command BP node, (I am not using PIE but uproject->Launch Game with editor closed), then the game permanently hangs!

86966-permahang.jpg

If you try to use Demoplay via a ConsoleCommand blueprint node, it hangs the game forever!

This is a critical bug because it means the only way to play a demo is by telling players to type into the console, which means a non-shipping build.

This bug basically prevents using demo recording in a full game release.

#Repro

Make sure to do these tests only when editor is closed, by right clicking on .uproject and Launch Game

  • record a replay, making sure to use open ?listen first, and then in the console type “demorec test”
  • when satisified, do console command “demostop”
  • reload the game, either with open ?listen or close and re-launch the game
  • in console command type “demoplay test”
  • everything will be fine!
  • reload the game, and press p, game will hang forever, and all I did was ExecuteConsoleCommand “demoplay test” via blueprint node in custom player controller class

#Sample Project

I am providing you with a sample project that you can run to see this hang!
www.lightningfitness.org/misc/video/DemoPlayHang.zip

I included the save folder in my sample project, you can simply run the game via right click on .uproject and “Launch Game/” then press P, and game will hang forever.

I already recorded the replay for you, its called “test”

If you want to do it yourself, you can follow my steps above!

In the editor, you can check out my PC blueprint under BP folder, it contains only this, which causes the hang:

#Conclusion ~ Demo Replay system totally unusable in 4.11

The demo replay system is unviable in a final product because users have to enter into the console directly, again I am testing this in a bp-only project with a maximm of 2 custom nodes, key event and execute console command.

#:heart:

Rama

2

#More Info

#Hang 2
I wrote a BP node to call the GameInstance function directly, running that inside my player controller on key press ALSO permanently hangs the game

UFUNCTION(BlueprintCallable, Category = "PO BP Library",meta=(WorldContext="WorldContextObject" ))
	static void PlayReplay(UObject* WorldContextObject, FString ReplayName)
	{
		UWorld* const World = GEngine->GetWorldFromContextObject(WorldContextObject);
		if(!World) return ;
		   
		World->GetGameInstance()->PlayReplay(ReplayName);
	}

Hang 3

Running this BP node from level BP ALSO crashes the game

#Question

Why is it that the only way I can load a replay in 4.11 in a BP only project is via actually opening the console and typing in demoplay test?

If I try to do it any other way, the game perma-hangs

#Thanks! :heart:

Rama

3

Hey Rama,

Thank you for the test project and all of the extra info. I was able to reproduce the issue, so I created JIRA UE-29545 and our developers will be looking into it further.

There is also another JIRA logged (UE-23342) that could be the root cause of this. I decided to create your JIRA instead of piggybacking on it because the repro is different.

Cheers,

TJ

4

Thank you very much for the update TJ!

#:heart:

Rama

5

Hi,

As we’re having the same issue here, I’d like to know if you’ve found some fix or workaround ?
You’re mentioning Jira bugtracker, but I’m not able to find a link to it. Is it private ?

Thans,

6

Hi jbg,

Yes, the JIRA system is currently private (although we do have plans to make this publicly visible in the future). This is currently fixed internally and if all goes well, it is on track to be included in the 4.12 release version.

As for a workaround, I’m not aware of one in the current version of the engine. But if you know of one @Rama, please feel free to chime in.

7

Thanks !

I’ll stay tuned. I don’t think we’ll be able to wait for 4.12, but as soon as the fix is available on perforce, I’ll try to back port it.

8

If you have Perforce access, here is the CL for the fix in the 4.12 Releases Stream.

CL-295331

If you need anything else, just let me know.

9

I’m having this issue aswell in version 4.15

10

Hi DoubleP90,

I attempted to reproduce the issue from both of the JIRAs that I mentioned above and they are fixed in 4.15. This is likely a different issue altogether. Please post a new report in the Bug section and include exact repro steps and/or a test project.

Cheers,

TJ