The directory name is invalid (4282076)

The following error occurs when opening Email Viewer:

System.IO.IOException: The directory name is invalid.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.Path.GetTempFileName()
   at EmailViewerAsp.Control.MessageWrapper.MsgEmailItem..ctor(Stream stream)
   at EmailViewerAsp.Control.SPItemWrapper.get_MimeItem()
   at EmailViewerAsp.Control.SPItemWrapper.GetProperty[T](IEmailProperty prop)
   at EmailViewerAsp.Control.EmailViewer.GetItem(String listUrl, String itemID)
   at EmailViewerAsp.Control.EmailViewer.OnInit(EventArgs e)

Required permissions are missing on the folder under which the SharePoint service is running.

1. "Everyone" needs to have permission to the user’s temp folder under which the SharePoint service is running. For example, the SharePoint service was running under the "Network Service" user (in a standalone SharePoint installation), so add Full Control permission for the C:\Windows\ServiceProfiles\NetworkService\AppData\Local\Temp folder. In case of non-special (AD) users, the folder will be on C:\Users\<UserName>\AppData\Local\Temp.

   NOTE: The Temp folder may be different. To confirm its path, run %temp% on the command line.

2. Turn off User Access Control (UAC) on the server.