NULL: Can't start an online game for session with BLUEPRINTS

Development Programming & Scripting Blueprint
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1

Hi,
i made a detailed post but it lost so i repeat it quick:

Im working on a multiplayer game, i was able to do a game play session over steam by using shooter template with our assets without problems.
also multiplayer shootout template works as expected.

Then i wanted to create everything from scratch,
now i get:

 NULL: Can't start an online game for session (Game) that hasn't been created

By using blueprints.
Either i am not able to host a session or i am not able to find a session… always not working

Please checkout these threads:

As adviced by :
([Bug Report] JoinSession doesnt work with warning "Invalid Player State" in 4.7.4 - Multiplayer & Networking - Epic Developer Community Forums)

no steam running: client verbose log no steam running server verbose log no steam running

steam running: client verbose log server verbose log

ue4_verbose_server.txt (35.7 kB)
ue4_verbose_client.txt (32.0 kB)
nosteamrunning_server.txt (35.7 kB)
nosteamrunning_client.txt (31.9 kB)

We need a tutorial to fill knowledge holes about STEAM, actually existing for many people NOT using shooter template.
Thank you for any help.

2

Hey ,

So this only occurs in your project, correct? First Person template and Multiplayer Shootout have no problems connecting? And this is in a packaged project? If you could upload this project (or another small test project that has same problem) someplace like Dropbox or Google Drive, that might prove helpful. You can send me a download link via PM on forums, if you’d like:

3

Hi ,

I got your project, and I’m looking into it now. Can you let me know if you’ve run through process described here?

Thanks!

4

hi ,
thank you for your help!
yes i ran through process and i can see steam overlay but im not able to connect over ip (internet) and im not able to find sessions over internet with 2 different steam accounts and forwarded port of 7777 and 27015

5

Hi ,

Sorry for delay, I was out sick for a while and I’m getting back to testing this issue for you now. Quick question: are you using whitelisted Steam accounts for these tests?

6

hi ,
best health to you!
Just tested with latest packaged project after many hours struggling with packaging errors.
Still not working multiplayer over steam, if uses start hosting local with parameter -NOSTEAM and launching 2x they can find their own session.
But not over steam / internet!
clients are not whitelisted but Shooter Template and Multiplayer Shootout both work over Steam and same conditions.

thank you for any help and thank you thousand times for any fast help especially

7

please don’t forget me, this is really important for me, as we want to release near winter

8

Hi ,

Haven’t forgotten about you. I’ll get back to you as soon as we can. Thanks for your patience!

9

Hey ,

It looks like this may be result of Advanced Sessions Plugin that you’re using. I’m still attempting to confirm (at moment, simply replacing Advanced nodes with standard nodes will cause project to not package correctly, so I haven’t had a successful test), but that would explain why this works with our Multiplayer Shootout project and not yours because setup is nearly identical otherwise.

Can you take a look and see if you can get this working correctly without plugin and see if you can get a connection? I’ll keep trying here as well.

10

I took another look, and one of requirements for using this plugin properly is to make sure your game instance is derived from AdvancedFriendsGameInstance. Yours derives from a custom GameInstance class that you created, SnowballGameInstance, which is NOT derived from AdvancedFriendsGameInstance.

Try recreating BP_Snowball_GameInstance, this time deriving it from AdvancedFriendsGameInstance instead. According to plugin’s forums page, that’s what you need to do to be able to join a session using Online Subsystem.

11

Or reparent it. There might be problems with that, given how much you already have in your game instance, but it’d be first thing i’d try.

12

thank you so much, i will check out immediately!
awesome your support!
thumbs up!

13

Hello, I’m author of Advanced Sessions Plugin.

plugin doesn’t require that you re-parent your game instance unless you want join through friend invite functionality. I realize looking back at my text that it is worded a little badly there and have fixed it in my post.

gameinstance shouldn’t be cause of any issues with creating a session. Also it has been tested and is fully working with steam for multiple people including myself (it was made with a focus on that platform).

I have had engine throw the “NULL: Can’t start an online game for session (Game) that hasn’t been created” warning during in editor builds (not packaged builds) but it has never affected actually hosting server for me.

I don’t have example project to look at so just throwing some things out there in hopes it clears up some confusion.