An error occurred during the processing of a configuration file required to service this request

Issue:

An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

• Server Error in '/' Application.

  ---

  Configuration Error

  Description:An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
  
  Parser Error Message: It is an error to use a section registered as allowDefinition='MachineToApplication' beyond application level. This error can be caused by a virtual directory not being configured as an application in IIS.
  
  Source Error:
  
  

  Line 74: ASP.NET to identify an incoming user. Line 75: --> Line 76: <authentication mode="Forms" /> Line 77: <!-- Line 78: The <customErrors> section enables configuration

  
  Source File: C:\inetpub\vhosts\primetravels.in\httpdocs\admin\web.config Line:76
  
  

  ---

  Version Information: Microsoft .NET Framework Version:2.0.50727.5420; ASP.NET Version:2.0.50727.5420

Solution:

We have to make sure our virtual directory is configured as an application in IIS.
if you created the web application and try to create the virtual directory for the web site. you will get the above error. Simple resolution is

Go to your IIS--> Click site --> choose the virtual directory site (you have configured)--> then convert to application.  that's it. :)

Note: Please make sure you have admin access to the site and add Network Service role to web site in the permission tab if you use IIS 7 and above.