MVC:Entity Framework Exception “The underlying provider failed on Open”

http://stack247.wordpress.com/2011/03/02/entity-framework-exception-the-underlying-provider-failed-on-open/ When trying to query data from Entity Framework, my code always return the following error: The underlying provider failed on Open. Turn out the problem was on the Connection String for the entity. In the config file, we have to include “Password” parameter in “connectionString” attribute. it works now!