Exception message: Server cannot append header after HTTP headers have been sent : how to solve this issue

HI

In a sharepoint intranet farm  below error appeared many times for diffrent images in style library folder.

in this farm it has 1.WFE server and 1.Application server.

Log Name:      Application

Source:        ASP.NET 2.0.50727.0

Date:          24/11/36 12:03:20 م

Event ID:      1309

Task Category: Web Event

Level:         Warning

Keywords:      Classic

User:          N/A

Computer:      XXXSPDV01.xxx.local

Description:

Event code: 3005

Event message: An unhandled exception has occurred.

Event time: 24/11/36 12:03:20 م

Event time (UTC): 24/11/36 09:03:20 ص

Event ID: d40446bd7e5b4e6c913246f492d0b93d

Event sequence: 9734

Event occurrence: 48

Event detail code: 0

Application information:

    Application domain: /LM/W3SVC/838794701/ROOT-1-130861762583645739

    Trust level: WSS_Minimal

    Application Virtual Path: /

    Application Path: C:\inetpub\wwwroot\wss\VirtualDirectories\80\

    Machine name: XXXSPDV01

Process information:

    Process ID: 10352

    Process name: w3wp.exe

    Account name: XXX\spfarm

Exception information:

    Exception type: HttpException

    Exception message: Server cannot append header after HTTP headers have been sent.

Request information:

    Request URL: http://intranet.xxx.sa/Style Library/Images/alert.gif

    Request path: /Style Library/Images/alert.gif

    User host address:

   User: 0#.w|xxx\xx

    Is authenticated: True

    Authentication Type: Federation

    Thread account name: XXX\spfarm

Thread information:

    Thread ID: 5

    Thread account name: XXX\spfarm

    Is impersonating: False

    Stack trace:    at System.Web.HttpResponse.AppendHeader(String name, String value)

   at Microsoft.SharePoint.Publishing.BlobCache.SetResponseHeaders(HttpContext context, BlobCacheEntry target)

   at Microsoft.SharePoint.Publishing.BlobCache.SendCachedFile(HttpContext context, BlobCacheEntry target, SPUserToken currentUserToken, SiteEntry currentSiteEntry)

   at Microsoft.SharePoint.Publishing.BlobCache.SendCachedFile(HttpContext context, BlobCacheEntry target, SiteEntry currentSiteEntry)

   at Microsoft.SharePoint.Publishing.BlobCache.HandleCachedFile(HttpContext context, BlobCacheEntry target, Boolean anonymousUser, SiteEntry currentSiteEntry, Boolean preAuthenticate)

   at Microsoft.SharePoint.Publishing.BlobCache.RewriteUrl(Object sender, EventArgs e, Boolean preAuthenticate)

   at Microsoft.SharePoint.Publishing.PublishingHttpModule.AuthorizeRequestHandler(Object sender, EventArgs ea)

   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Custom event details:

Event Xml:

<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">

  <System>

    <Provider Name="ASP.NET 2.0.50727.0" />

    <EventID Qualifiers="32768">1309</EventID>

    <Level>3</Level>

    <Task>3</Task>

    <Keywords>0x80000000000000</Keywords>

    <TimeCreated SystemTime="2015-09-08T09:03:20.000000000Z" />

    <EventRecordID>60389623</EventRecordID>

    <Channel>Application</Channel>

    <Computer>XXXSPDV01.xxx.local</Computer>

    <Security />

  </System>

  <EventData>

    <Data>3005</Data>

    <Data>An unhandled exception has occurred.</Data>

       <Data>WSS_Minimal</Data>

    <Data>/</Data>

    <Data>C:\inetpub\wwwroot\wss\VirtualDirectories\80\</Data>

    <Data>XXXSPDV01</Data>

    <Data>

    </Data>

    <Data>10352</Data>

    <Data>w3wp.exe</Data>

    <Data>XXX\spfarm</Data>

    <Data>HttpException</Data>

    <Data>Server cannot append header after HTTP headers have been sent.</Data>

    <Data>http://intranet.xxx.sa/Style Library/Images/alert.gif</Data>

    <Data>/Style Library/Images/alert.gif</Data>

    <Data>10.21.198.11</Data>

    <Data>0#.w|xxx\xxx</Data>

    <Data>True</Data>

    <Data>Federation</Data>

    <Data>XXX\spfarm</Data>

    <Data>5</Data>

    <Data>XXX\spfarm</Data>

    <Data>False</Data>

    <Data>   at System.Web.HttpResponse.AppendHeader(String name, String value)

   at Microsoft.SharePoint.Publishing.BlobCache.SetResponseHeaders(HttpContext context, BlobCacheEntry target)

   at Microsoft.SharePoint.Publishing.BlobCache.SendCachedFile(HttpContext context, BlobCacheEntry target, SPUserToken currentUserToken, SiteEntry currentSiteEntry)

   at Microsoft.SharePoint.Publishing.BlobCache.SendCachedFile(HttpContext context, BlobCacheEntry target, SiteEntry currentSiteEntry)

   at Microsoft.SharePoint.Publishing.BlobCache.HandleCachedFile(HttpContext context, BlobCacheEntry target, Boolean anonymousUser, SiteEntry currentSiteEntry, Boolean preAuthenticate)

   at Microsoft.SharePoint.Publishing.BlobCache.RewriteUrl(Object sender, EventArgs e, Boolean preAuthenticate)

   at Microsoft.SharePoint.Publishing.PublishingHttpModule.AuthorizeRequestHandler(Object sender, EventArgs ea)

   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously)

</Data>

  </EventData>

</Event>

adil