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Project 25 - app crashes when try to " Host a session"

Forums > 100 Days of Swift

Hey Guys, is anyone else having trouble with just trying to host a session? My app crashes immedietly (both on my phone or in simulator) when attempted, with this error message : Thread 1: "-[MCAdvertiserAssistant advertiser:didNotStartAdvertisingPeer:]: unrecognized selector sent to instance 0x2834b8fc0"

I read through the other 2 forums related to project 25 and made the changes below:

  1. Go to Info.plist in your project and delete Application Scene Manifest row.
  2. Go to AppDelegate.swift and add var window: UIWindow? in the class.
  3. In the same class, delete everything below // MARK: UISceneSession Lifecycle line.

BUT it still didn't work for me.



Your problem stems from Apple's shenanigans introduced along with iOS 14.

Try to insert the following fields in the info.plist:

  1. Privacy - Local Network Usage Description
  2. Bonjour services with the following initialisation: _service._tcp and _service._udp

Hope it helps!



I'm having issues as well. I tried both of what teekachu and MateusZ have written. Simulator doesn't give errors whether I select host or select join session, but it does prompt to accept incoming network connections (probably a macOS thing). My iPhone does not prompt to accept connections, and I get an errors with both host and join session selection. When I select host session:

2020-10-02 16:44:40.563044-0500 SelfieShare[2894:993220] [MCNearbyServiceAdvertiser] Server did not publish: errorDict [{
    NSNetServicesErrorCode = "-72008";
    NSNetServicesErrorDomain = 10;
2020-10-02 16:44:40.563461-0500 SelfieShare[2894:992948] -[MCAdvertiserAssistant advertiser:didNotStartAdvertisingPeer:]: unrecognized selector sent to instance 0x283c51340
2020-10-02 16:44:40.563924-0500 SelfieShare[2894:992948] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[MCAdvertiserAssistant advertiser:didNotStartAdvertisingPeer:]: unrecognized selector sent to instance 0x283c51340'

When I select join session, the error is almost the same, but basically has "Browser" instead of "Advertiser".

Xcode 12, iOS 14


@poke-peek, did you replace _service in _service._tcp and _service._udp with what you use when initializing MCAdvertiserAssistant, in my case serviceType is bball-service so I had to add _bball-service._tcp and _bball-service._udp in the plist file.


@ladislavklinc - that's correct and thank you for info and guides ...

just for clarification for others [ my case]:

mcAdvertiserAssistant = MCAdvertiserAssistant(serviceType: "cp-project25", discoveryInfo: nil, session: mcSession)


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