IIS stops responding to http requests

Hi everyone.

We have an ASP.NET application based on .NET Framework 4.5. Sometimes it stops responding to web requests. Unfortunately it happens randomly and I can not reproduce it.

Here is the last error details from Event Viewer:

Event code: 3005 
Event message: An unhandled exception has occurred. 
Event time: 4/5/2016 11:23:34 AM 
Event time (UTC): 4/5/2016 6:53:34 AM 
Event ID: 2cb5a099770f41d3963a25c821590c1e 
Event sequence: 109 
Event occurrence: 1 
Event detail code: 0 
Application information: 
    Application domain: /LM/W3SVC/2/ROOT-8-131043125735578370 
    Trust level: Full 
    Application Virtual Path: / 
    Application Path: C:\Users\<myusername>\Documents\Visual Studio 2015\Projects\PayamGostar\Dev\PresentationLayer\Web\Portals\WebUI\ 
    Machine name: DEV08 
Process information: 
    Process ID: 8068 
    Process name: w3wp.exe 
    Account name: IIS APPPOOL\pgonline-dev 
Exception information: 
    Exception type: ApplicationException 
    Exception message: Catastrophic failure (Exception from HRESULT: 0x8000FFFF (E_UNEXPECTED))
   at System.Threading.ReaderWriterLock.ReleaseWriterLockInternal()
   at System.Configuration.Internal.InternalConfigRoot.GetConfigRecord(String configPath)
   at System.Configuration.Internal.InternalConfigRoot.GetUniqueConfigRecord(String configPath)
   at System.Web.CachedPathData.Init(CachedPathData parentData)
   at System.Web.CachedPathData.GetConfigPathData(String configPath)
   at System.Web.CachedPathData.GetConfigPathData(String configPath)
   at System.Web.CachedPathData.GetConfigPathData(String configPath)
   at System.Web.HttpContext.GetFilePathData()
   at System.Web.Configuration.RuntimeConfig.GetConfig(HttpContext context)
   at System.Web.HttpContext.SetImpersonationEnabled()
   at System.Web.HttpApplication.AssignContext(HttpContext context)
   at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)

 
 
Request information: 
    Request URL: http://pgonline-dev.com/MyFirst/Crm/Reminder.aspx/HasRemindersToNotify 
    Request path: /MyFirst/Crm/Reminder.aspx/HasRemindersToNotify 
    User host address: 127.0.0.1 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: IIS APPPOOL\pgonline-dev 
 
Thread information: 
    Thread ID: 5 
    Thread account name: IIS APPPOOL\pgonline-dev 
    Is impersonating: False 
    Stack trace:    at System.Threading.ReaderWriterLock.ReleaseWriterLockInternal()
   at System.Configuration.Internal.InternalConfigRoot.GetConfigRecord(String configPath)
   at System.Configuration.Internal.InternalConfigRoot.GetUniqueConfigRecord(String configPath)
   at System.Web.CachedPathData.Init(CachedPathData parentData)
   at System.Web.CachedPathData.GetConfigPathData(String configPath)
   at System.Web.CachedPathData.GetConfigPathData(String configPath)
   at System.Web.CachedPathData.GetConfigPathData(String configPath)
   at System.Web.HttpContext.GetFilePathData()
   at System.Web.Configuration.RuntimeConfig.GetConfig(HttpContext context)
   at System.Web.HttpContext.SetImpersonationEnabled()
   at System.Web.HttpApplication.AssignContext(HttpContext context)
   at System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context)
 
 
Custom event details: 

Method named HasRemindersToNotify is a WebMethod in page Reminder.aspx is a simple query to database.

System Details:

Microsoft Windows 10 Build 10586.0

IIS version 10.0.10586.0

.NET Framework verion 4.5

Thanks in advance