Request for the permission of type 'Microsoft.SharePoint.Security.SharePointPermission, Microsoft.SharePoint.Security, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c' failed

This is the one of the strange errors when working with sharepoint.

Cause for he error :

This is because sharepoint by default is provided with the minimal trust permission level.

For some operations we need trust from the security policy.

Solution :

This requires change in the Trust Level in Web.Config file of the Web app.

Go to web.config file of the web application usually this will be located in

C:\inetpub\wwwroot\wss\VirtualDirectories\[Web application directory]

and open the web.config and change the

trust level="WSS_Minimal" to trust level="WSS_Medium"

or

trust level="WSS_Minimal" to trust level="Full"

Happy coding !!