Some times while debugging a web application in Visual Studio, I run into error similar to the one below. The error does not go away even when Aspnet_wp.exe process is killed and IIS restarted. Parser Error Message: Access is denied It happens that the error message occurs when the Microsoft Index Server (Cisvc.exe) is running on your machine. Cisvc.exe holds a lock on the Temporary ASP.NET Files directory. For a quick fix, kill the Cisvc.exe. For a permanent fix exclude the temporary ASP.NET files directory from being indexed by the index server. More on the error can be found at MSDN .