UNet WebGL Uncaught TypeError: Cannot read property 'id' of null

Has anyone encountered this problem?

  1. Create project in Unity version 5.5.0f3
  2. Create NetworkManager (use WebSockets) and NetworkManager HUD
  3. Build & Run WebGL ( my browser is Google Chrome )
  4. Click LAN Client: Connect, Disconnect, Connect, Disconnect
  5. After second disconnect WebGL crashed with Uncaught TypeError: Cannot read property ‘id’ of null

blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:7456 Uncaught TypeError: Cannot read property ‘id’ of null
at _JS_UNETWebSockets_HostsContainingMessagesCleanHost (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:7456:57)
at _JS_UNETWebSockets_SocketCleanEvntFromHost (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:13568:3)
at _UNETWebSocketLib_ReceiveFromHost_m2241654441 (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:1800058:3)
at _NetworkTransport_ReceiveFromHost_m3839023694 (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2586125:9)
at Array._NetworkClient_Update_m3929415511 (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:818023:9)
at __ZN18VirtActionInvoker06InvokeEjPv (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2802312:45)
at _NetworkClient_UpdateClients_m3019586081 (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2065744:4)
at Array._NetworkIdentity_UNetStaticUpdate_m2136578454 (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2456095:2)
at Array._Z31RuntimeInvoker_Void_t1841601450PK10MethodInfoPvPS2 (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2974030:45)
at Object.dynCall_iiii (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2996577:40)
at invoke_iiii (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:16841:32)
at __ZN6il2cpp2vm7Runtime6InvokeEPK10MethodInfoPvPS5_PP15Il2CppException (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2477258:8)
at _il2cpp_runtime_invoke (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2881140:9)
at __Z23scripting_method_invoke21ScriptingMethodIl2CppP12Il2CppObjectR18ScriptingArgumentsPP15Il2CppExceptionb (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2650451:8)
at __ZN19ScriptingInvocation6InvokeEPP15Il2CppExceptionb (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:1945284:7)
at Array.__ZZN4UNET16ScriptingUpdater4InitEvEN29PreLateUpdateUNetUpdatestruct7ForwardEv (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2481963:2)
at __Z10PlayerLoopv (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:812694:40)
at Array.__ZL8MainLoopv (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:1995293:3)
at dynCall_v (blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:3075991:28)
at Object.dynCall (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:299:36)
at browserIterationFunc (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:1979:12)
at Object.runIter (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:2081:5)
at Browser_mainLoop_runner (blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:2017:20)_JS_UNETWebSockets_HostsContainingMessagesCleanHost @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:7456_JS_UNETWebSockets_SocketCleanEvntFromHost @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:13568_UNETWebSocketLib_ReceiveFromHost_m2241654441 @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:1800058_NetworkTransport_ReceiveFromHost_m3839023694 @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2586125_NetworkClient_Update_m3929415511 @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:818023__ZN18VirtActionInvoker06InvokeEjPv @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2802312_NetworkClient_UpdateClients_m3019586081 @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2065744_NetworkIdentity_UNetStaticUpdate_m2136578454 @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2456095__Z31RuntimeInvoker_Void_t1841601450PK10MethodInfoPvPS2_ @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2974030dynCall_iiii @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2996577invoke_iiii @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:16841__ZN6il2cpp2vm7Runtime6InvokeEPK10MethodInfoPvPS5_PP15Il2CppException @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2477258_il2cpp_runtime_invoke @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2881140__Z23scripting_method_invoke21ScriptingMethodIl2CppP12Il2CppObjectR18ScriptingArgumentsPP15Il2CppExceptionb @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2650451__ZN19ScriptingInvocation6InvokeEPP15Il2CppExceptionb @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:1945284__ZZN4UNET16ScriptingUpdater4InitEvEN29PreLateUpdateUNetUpdatestruct7ForwardEv @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:2481963__Z10PlayerLoopv @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:812694__ZL8MainLoopv @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:1995293dynCall_v @ blob:http://localhost:57221/6d0737e2-61bd-4325-8610-86cdcbd46d21:3075991dynCall @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:299browserIterationFunc @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:1979runIter @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:2081Browser_mainLoop_runner @ blob:http://localhost:57221/05648501-bbdf-4ba6-9ed5-66d974f8f72d:2017

Did you solve this?

Hello,
this is a known bug right now. Sorry for the troubles. You can follow its resolution and vote for it at Unity Issue Tracker - NetworkManagerHUD "Uncaught TypeError: Cannot read property 'id' of null" thrown when clicking Lan Client on WebGL build

Template fix this: Disconnect from server (Unet, WebGL). - Unity Engine - Unity Discussions

Is this fixed now ?
I am using unity 2017.4.3f1 and i still got the error.

Dont fixed (2018.1.3)

This issue is still there (2018.2.16f1)

Still persist