The database was causing an error. I have found the solution. what we need to do? We need to add a login to SQL Server
for IIS APPPOOL\ASP.NET v4.0
and grant permissions to the database.
In SQL Server Management, under the server, expand Security, then right click the Logins and select "New Login...".
In the New Login dialog, enter the app pool as the login name and click "OK"
now right click the login, select properties and then click on the User Mapping Option. Click the appropriate DATABASE and check the properties roles. And we are done :).
hope you good luck. Thanks