I’ve been having this same issue, but only with Android connecting to a dedicated server. Windows can still connect.
It seems to be caused by attempting to use OnlineSubsystemUNSET. But I’ve selected to use OnlineSubsystemOculus, and I’m in the process of figuring out why it appears to be UNSET instead.
Here are some of my logs around this:
UE4 : [2018.12.07-22.53.35:481][522]LogGameMode: Display: Match State Changed from InProgress to LeavingMap
UE4 : [2018.12.07-22.53.35:481][522]LogGameState: Match State Changed from InProgress to LeavingMap
UE4 : [2018.12.07-22.53.35:481][522]LogNet: Browse: 35.197.7.152//Game/SculptureMode
UE4 : [2018.12.07-22.53.35:482][522]LogInit: BSD_Android: Socket queue 65536 / 65536
UE4 : [2018.12.07-22.53.35:483][522]LogInit: BSD_Android: I am localhost (127.0.0.1:0)
UE4 : [2018.12.07-22.53.35:483][522]LogSockets: (BSD_Android) Wifi Adapter IP 127.0.0.1
UE4 : [2018.12.07-22.53.35:484][522]PacketHandlerLog: Loaded PacketHandler component: Engine.EngineHandlerComponentFactory (StatelessConnectHandlerComponent)
UE4 : [2018.12.07-22.53.35:484][522]LogNet: Game client on port 7777, rate 500000000
UE4 : [2018.12.07-22.53.35:676][536]LogNetVersion: SculptrVR 1.0.0.0, NetCL: 0, EngineNetVer: 5, GameNetVer: 0 (Checksum: 1388534187)
UE4 : [2018.12.07-22.53.35:677][536]LogNet: UPendingNetGame::SendInitialJoin: Sending hello. [UNetConnection] RemoteAddr: 35.197.7.152:7777, Name: IpConnection_0, Driver: PendingNetDriver IpNetDriver_0, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID
UE4 : [2018.12.07-22.53.35:718][539]LogModuleManager: Warning: ModuleManager: Module ‘OnlineSubsystemUNSET’ not found - its StaticallyLinkedModuleInitializers function is null.
UE4 : [2018.12.07-22.53.35:788][544]LogNet: NetConnection::Close() [PendingNetDriver] [NoPC] [No Owner] from NMT_Failure incompatible_unique_net_id