# Can't launch UEFN session

**URL:** <https://forums.unrealengine.com/t/cant-launch-uefn-session/2052065>\
**Category:** Issues and Bug Reporting\
**Tags:** fortnite-creative, unreal-editor-for-fortnite, fortnite\
**Created:** [October 3, 2024, 9:25pm UTC](https://forums.unrealengine.com/t/cant-launch-uefn-session/2052065 "2024-10-03T21:25:05Z")\
**Posts on this page:** 1\
**Showing post:** 11

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**Author:** ![LarYye](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@LarYye](https://forums.unrealengine.com/u/LarYye)\
**Post date:** [October 7, 2024, 1:26pm UTC](https://forums.unrealengine.com/t/cant-launch-uefn-session/2052065/11 "2024-10-07T13:26:26Z")

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I solved the error about the save the world files, had to enable and install it from the epic games launcher, also verified the uefn files again

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/0/a/e0a6ec655c8fcdf62a6379d1ac1e633680dded9d.png)

But now the issue remaining is this one when i try to launch, it loads but disconnects, then shows these warnings:

> LogUObjectGlobals: Warning: Failed to find object ‘Class /Script/MediaPlate.MediaPlateResource’  
> LogNet: Warning: Channel name will be serialized as a string: ValkyrieBeacon  
> LogHttp: Warning: HttpRetry: Resetting log verbosity to Warning due to requests being retried

When I try to load the second time, it shows this:

> LogOnlineSession: Warning: MCP: FindSingleSession request failed. Invalid response. code=404 error={  
> “errorCode” : “errors.com.epicgames.modules.matchmaking.unknown\_session”,  
> “errorMessage” : “unknown session id d82f903575c04491a649be0d813ccad2”,  
> “messageVars” : [“d82f903575c04491a649be0d813ccad2”],  
> “numericErrorCode” : 12101,  
> “originatingService” : “fortnite”,  
> “intent” : “prod-live”  
> }  
> LogOnline: Warning: OSS: Async task ‘FOnlineAsyncTaskMcpFindSingleSession bWasSuccessful: 0’ failed in 0.123488 seconds  
> LogValkyrieAccount: [UValkyrieOnlineInstance::ApplyUserPreferredQoSRegion] Region Auto: BR  
> LogValkyrie: ProjectSizeRequest::GetDependencyDownloadSizes for de8ab965-4682-0b7f-c5c4-778351763f50  
> LogValkyrie: ProjectSizeRequest::Completed for de8ab965-4682-0b7f-c5c4-778351763f50  
> LogNet: Warning: Channel name will be serialized as a string: ValkyrieBeacon

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