title: Access violation issue in Silverlight Application
body: <p>We are having Silverlight application which shows live data from the service onto the client.</p>
  
  <p>Over a period of time we see that application gets hung and on refresh the IE crashes with with the error message saying internet has stopped working.\</p>
  
  <p>On taking the dump and analyzing it using debugdiag we found that the callstack of it shows,</p>
  
  <pre><code>0x00000000
  npctrl!ComAutomationCheckCrossApartmentAccess+d079
  mshtml!ReleaseInterface+a
  mshtml!CAttrArray::FreeSpecial2+e4
  mshtml!CMarkup::BreakAASpecial+f
  mshtml!CMarkup::BreakCircularMemoryReferences+eb
  mshtml!CMarkup::UnloadContents+36f
  mshtml!CMarkup::TearDownMarkupHelper+53
  mshtml!CMarkup::TearDownMarkup+54
  mshtml!COmWindowProxy::SwitchMarkup+5c5
  mshtml!CMarkup::SetInteractiveInternal+134
  mshtml!CMarkup::RequestReadystateInteractive+6c
  mshtml!CMarkup::BlockScriptExecutionHelper+162
  mshtml!CHtmPost::Exec+418
  mshtml!CHtmPost::Run+15
  mshtml!PostManExecute+1fd
  mshtml!PostManResume+f8
  mshtml!CHtmPost::OnDwnChanCallback+10
  mshtml!CDwnChan::OnMethodCall+19
  mshtml!GlobalWndOnMethodCall+104
  mshtml!GlobalWndProc+183
  user32!InternalCallWinProc+28
  user32!UserCallWinProcCheckWow+150
  user32!DispatchMessageWorker+306
  user32!DispatchMessageW+f
  ieframe!CTabWindow::_TabWindowThreadProc+54c
  ieframe!LCIETab_ThreadProc+2c1
  iertutil!CIsoScope::RegisterThread+ab
  kernel32!BaseThreadStart+37
  </code></pre>
  
  <p>We are not able to analyze this any further as it does not give a meaningful analysis. </p>
  
  <p>What is npctrl.dll and why it? Why is it giving ComAutomationCheckCrossApartmentAccess error?</p>