Hi,
I get error when my app wants to replace "NAppUpdate.Framework.dll". 
During update process, when files are replaced by "NAppUpdate.Updater" process I get exception:
2014 18:14:21.217      Error    
Could not replace the file
System.UnauthorizedAccessException: Access to the path '...\bin\Debug\NAppUpdate.Framework.dll' is denied.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.File.Delete(String path)
   at NAppUpdate.Framework.Tasks.FileUpdateTask.Execute(Boolean coldRun)
15.09.2014 18:14:21.217      Debug        Task execution failed
15.09.2014 18:14:22.791      Error    Update failed
This is caused because my app uses this file, but when I add this:
Thread.Sleep(100); 
In place 
https://github.com/synhershko/NAppUpdate/blob/master/src/NAppUpdate.Updater/AppStart.cs#L118Everything works.
I know this is ugly solution. 
Maybe do you know better solution of this problem ?