Hi guys, it appears that my SharePoint keeps getting error randomly when I first visit the page. Something like this will pop up

Error

An
unexpected error has occurred.

Troubleshoot
issues with Microsoft SharePoint Foundation.

Correlation ID:
4f48c122-f2f2-4679-b49b-c4a8dc9e4b4c

Date and Time: 8/18/2015 3:10:16
PM

Go back to site

When I press go back to site, or refresh page, everything works fine again. Any idea why?

Updated:

I have referred to the server log:

and this is the error I actually gets

08/18/2015 16:09:34.72  w3wp.exe (0x10A4)                        0x10C8 SharePoint Foundation          Monitoring                     nasq Medium   Entering monitored scope (Request (GET:http://server:80/SitePages/Home.aspx)) 
08/18/2015 16:09:34.72  w3wp.exe (0x10A4)                        0x10C8 SharePoint Foundation          Logging Correlation Data       xmnv Medium   Name=Request (GET:http://server:80/SitePages/Home.aspx) f9d6d40f-e852-40eb-933e-6ced3332c732
08/18/2015 16:09:34.72  w3wp.exe (0x10A4)                        0x10C8 SharePoint Foundation          Runtime                        tkau Unexpected System.InvalidOperationException: Operation is not valid due to the current state of the object.    at Microsoft.SharePoint.WebControls.SPControl.EnsureSPWebRequest(SPWeb web)     at Microsoft.SharePoint.WebControls.SPControl.SPWebEnsureSPControl(HttpContext context)     at Microsoft.SharePoint.ApplicationRuntime.SPRequestModule.GetContextWeb(HttpContext context)     at Microsoft.SharePoint.ApplicationRuntime.SPRequestModule.PostResolveRequestCacheHandler(Object oSender, EventArgs ea)     at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()     at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) f9d6d40f-e852-40eb-933e-6ced3332c732
08/18/2015 16:09:34.72  w3wp.exe (0x10A4)                        0x10C8 SharePoint Foundation          General                        8e2s Medium   Unknown SPRequest error occurred. More information: 0x80070005 f9d6d40f-e852-40eb-933e-6ced3332c732
08/18/2015 16:09:34.73  w3wp.exe (0x10A4)                        0x10C8 SharePoint Foundation          Monitoring                     b4ly Medium   Leaving Monitored Scope (Request (GET:http://server:80/SitePages/Home.aspx)). Execution Time=6.28368968681774 f9d6d40f-e852-40eb-933e-6ced3332c732

Does anyone knows how to help this?

• Edited by Kai Arthur Tuesday, August 18, 2015 8:18 AM

FYI,

http://sharepoint.stackexchange.com/questions/100778/unexpected-error-even-before-login-prompt

has the same error that I have faced.

Problem has been resolved. It appears to be web.config problem.

I have set impersonate=false in web.config, causing that issue.

• Marked as answer by Kai Arthur 38 minutes ago