Hi, I experienced a similar issue and it was because my VS.NET solution was targeting .net framework v4.5, switching to framework v4 and all works perfectly, maybe you have the same?

Hmm, I've started to see this intermittant error now, can't work out what the cause is.... I've tried upgrading to SignalR v1.1.0 to see if that made and difference, it did not :-(

Checking: everything is 4.0! I checked back on my environment. Error is still there. Turning on the visual studio debugger does not make difference. I notice this error afer --- End of inner exception stack trace ---. This is about Microsoft.Owin:

Server stack trace: 

Exception rethrown at [0]: 

   at Microsoft.Owin.Host.SystemWeb.Infrastructure.ErrorState.<>c__DisplayClass1.<GetRethrowWithNoStackLossDelegate>b__0(Exception ex)

   at Microsoft.Owin.Host.SystemWeb.CallContextAsyncResult.End(IAsyncResult result)

   at System.Web.HttpApplication.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar)

---> (Inner Exception #0) System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.

   at LiveLogger.LogAppenderHub..ctor()

   --- End of inner exception stack trace ---

   at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)

   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)

   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache, StackCrawlMark& stackMark)

   at System.Activator.CreateInstance(Type type, Boolean nonPublic)

   at System.Activator.CreateInstance(Type type)

   at Microsoft.AspNet.SignalR.Hubs.DefaultHubActivator.Create(HubDescriptor descriptor)

   at Microsoft.AspNet.SignalR.Hubs.HubDispatcher.CreateHub(IRequest request, HubDescriptor descriptor, String connectionId, StateChangeTracker tracker, Boolean throwIfFailedToCreate)

   at Microsoft.AspNet.SignalR.Hubs.HubDispatcher.OnReceived(IRequest request, String connectionId, String data)

   at Microsoft.AspNet.SignalR.PersistentConnection.<>c__DisplayClassa.<>c__DisplayClassc.<ProcessRequest>b__7()

   at Microsoft.AspNet.SignalR.TaskAsyncHelper.<>c__DisplayClass3c.<FromMethod>b__3b()

   at Microsoft.AspNet.SignalR.TaskAsyncHelper.FromMethod[TResult](Func`1 func)<---

Can't get this issue out of my mind.

I noticed another error in the log:

2013-05-23 05:08:36,421 [5] ERROR umbraco.presentation.nodeFactory.UmbracoSiteMapProvider - [Thread 5] Error adding node 1079 to SiteMapProvider in loadNodes()

System.InvalidOperationException: Multiple nodes with the same URL '/' were found. XmlSiteMapProvider requires that sitemap nodes have unique URLs.

   at System.Web.StaticSiteMapProvider.AddNode(SiteMapNode node, SiteMapNode parentNode)

   at umbraco.presentation.nodeFactory.UmbracoSiteMapProvider.loadNodes(String parentId, SiteMapNode parentNode)

I fixed this error by removing the hostname mapping from the subnode, republishing, and then re-adding the hostname mapping. Guess what? Suddenly LiveLogger 'lives'....

I know what you mean, it has been bugging me also. I generally completely remove the sitemap element from the web config as it is only there for legacy support and it generally throws errors that you don't need (especially if you have more than one host).

I think the Owin issue is to do with startup as you can see it is being thrown by Umbraco.Core.UmbracoApplicationBase, I'm going to give it try with Umbraco v6.1beta as the statup handler has been changed to handle stability issues like the db not being ready. http://our.umbraco.org/Documentation/Reference/Events/application-startup Maybe that will sort it....

Hey Merijn, I think I've solved this issue! Do you fancy giving a v1.1.0-beta a test drive? Also in this release a fix for bootstrap takeover and update to v1.1 of SignalR

https://dl.dropboxusercontent.com/u/14453377/Live_Logger_for_Umbraco_1.1.0-beta.zip

Appreciate any feedback!

Thanks,

Jeavon

Jeavon,

Excuse me for not getting back earlier. The new version did not help solving on my environment. I tested Livelogger 1.1.1 in 6.1.2, problem still there.

I use kilnhg version control a lot these days. In discovered in this particular installation I used a slightly different newer version of Newtonsoft.Json.dll. (5.0.3.16014)). However  the old Newtonsoft.Json.xml version 4.5.11.15520 (from Umbraco 6.1.2 binaries) was still there. I removed the xml, and suddenly LiveLogger starts logging.

I'm not sure this actually solves the problem, because the small change in the bin folder could trigger another cache refresh (.NET dll cache?). However I guess I'm searching in the right direction here...

Merijn

Hi Merijn,

That's very odd as the error has been solved for me since v1.1. Can you check that all resources from v1.0.x have been deleted from your solution, especially the event registration file that was in App_Code, if that's still there it would continue to cause the issue.

Also probably a good idea to stick with Json.net v4 as shippped with Umbraco v6.1+

Jeavon

I just checked and the file in App_Code folder was called AppStart.cs, if its still there, delete it.

Hello,

I have the same problem "Umbraco.Core.UmbracoApplicationBase - [Thread 43] An unhandled exception occurred"

I downloaded new JSON files and replaced it in umbraco , both dll and xml, and working fine...

http://json.codeplex.com/releases/view/74287

Maybe you can put newer files to installation package?

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