[Solved]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.

When you try to run a Web application that isbuilt on the Microsoft .NET Framework, you may receive an error message that resembles the following:

 Server Error in '/' Application.

Configuration Error

Description: An erroroccurred during the processing of a configuration file required to service thisrequest. Please review the specific error details below and modify yourconfiguration file appropriately. 

Parser Error Message: Thismethod cannot be called during the application's pre-start initializationphase.

Source Error: 

It's hard to find any information on the topic but in myopinion enableSimpleMembership set to false in appsettings. For me this errorresolved by setting below code.

<appSettings>

  <add key="enableSimpleMembership" value="false" />

 </appSettings>