Hi Claus,

Perhaps you could try to have a look into the log files, /App_Data/Logs  to see if it can reveal some more information about why you are getting this error, if you know the exact day where the site has throw the error. I mean errors in the log are marked with [ERROR]

Hope this helps,

/Dennis

Hi Claus

What version of Umbraco are you running? And what changes have been made before this started to happen? Any new functionality deployed? Any new custom packages some backoffice tweaks based on the Umbraco API? Any 3rd party packages installed? How is the site hosted? Is it running shared hosting? Dedicated server, cloud hosting?

Sounds like some data not being saved in the correct format for some reason - Have you tried simply recycling the app pool? If that works there might be a chance the issue will appear again at a later stage though.

/Jan

Recycling the app pools fixes it. But thats not really a viable solution. It has happened twice in a week.
its Umbraco 7.1.4
Its on a shared server, but our own server.
We have a third party developing some stuff into the site, but not at the time these things happened. 

Log says:

2015-03-24 09:06:48,892 [26] ERROR Umbraco.Core.UmbracoApplicationBase - [Thread 38] An unhandled exception occurred
System.ArgumentNullException: String reference not set to an instance of a String.
Parameter name: name
   at System.Globalization.CultureInfo..ctor(String name, Boolean useUserOverride)
   at System.Globalization.CultureInfo..ctor(String name)
   at Umbraco.Web.Routing.PublishedContentRequestEngine.FindDomain()
   at Umbraco.Web.Routing.PublishedContentRequestEngine.PrepareRequest()
   at Umbraco.Web.UmbracoModule.ProcessRequest(HttpContextBase httpContext)
   at Umbraco.Web.UmbracoModule.<Init>b__a(Object sender, EventArgs e)
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
2015-03-24 09:06:49,766 [26] ERROR Umbraco.Core.UmbracoApplicationBase - [Thread 13] An unhandled exception occurred
System.ArgumentNullException: String reference not set to an instance of a String.
Parameter name: name
   at System.Globalization.CultureInfo..ctor(String name, Boolean useUserOverride)
   at System.Globalization.CultureInfo..ctor(String name)
   at Umbraco.Web.Routing.PublishedContentRequestEngine.FindDomain()
   at Umbraco.Web.Routing.PublishedContentRequestEngine.PrepareRequest()
   at Umbraco.Web.UmbracoModule.ProcessRequest(HttpContextBase httpContext)
   at Umbraco.Web.UmbracoModule.<Init>b__a(Object sender, EventArgs e)
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
2015-03-24 09:06:50,499 [26] ERROR Umbraco.Core.UmbracoApplicationBase - [Thread 32] An unhandled exception occurred
System.ArgumentException: Illegal characters in path.
   at System.IO.Path.CheckInvalidPathChars(String path, Boolean checkAdditional)
   at System.Security.Permissions.FileIOPermission.CheckIllegalCharacters(String[] str)
   at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access, AccessControlActions control, String[] pathListOrig, Boolean checkForDuplicates, Boolean needFullPath, Boolean copyPathList)
   at System.Security.Permissions.FileIOPermission..ctor(FileIOPermissionAccess access, String path)
   at System.Web.InternalSecurityPermissions.PathDiscovery(String path)
   at System.Web.HttpRequest.get_PhysicalPath()
   at UrlRewritingNet.Web.UrlRewriteModule.OnBeginRequest(Object sender, EventArgs e)
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
2015-03-24 09:06:50,499 [26] ERROR Umbraco.Core.UmbracoApplicationBase - [Thread 32] An unhandled exception occurred
System.ArgumentException: Illegal characters in path.
   at System.IO.Path.CheckInvalidPathChars(String path, Boolean checkAdditional)
   at System.Security.Permissions.FileIOPermission.CheckIllegalCharacters(String[] str)
   at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access, AccessControlActions control, String[] pathListOrig, Boolean checkForDuplicates, Boolean needFullPath, Boolean copyPathList)
   at System.Security.Permissions.FileIOPermission..ctor(FileIOPermissionAccess access, String path)
   at System.Web.InternalSecurityPermissions.PathDiscovery(String path)
   at System.Web.HttpRequest.get_PhysicalPath()
   at UrlRewritingNet.Web.UrlRewriteModule.OnBeginRequest(Object sender, EventArgs e)
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Hi Claus

Ok - But what kind of stuff is it? If it's things like property editors or other kind of backoffice stuff then it can perhaps cause it. But it can perhaps also be related to the traffic on the site - does it have ressources enough when the peak is high for instance?

/Jan

Hi Claus,

As Jan says, perhaps it could be be related to the traffic on the site. I found a post, where the person also get the System.ArgumentException:Illegal characters in path, you can see the post here: https://our.umbraco.org/forum/umbraco-7/using-umbraco-7/54467-High-CPU-on-a-713

And try to see the comment by Jeavon, https://our.umbraco.org/forum/umbraco-7/using-umbraco-7/54467-High-CPU-on-a-713?p=0#comment188656

Hope this can help you,

/Dennis

Hmmm, ive set up a perfmon logger on the cpu usage, so i have some data if it happens again. 

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