Error In Data Access

<h1>Error In Data Access</h1><hr/>Error Message: Error executing GetReader<hr /><b>Stack Trace: </b><br/>Dea.MasterCalendar.Utilities.DataAccess.c: Error executing GetReader ---> System.Data.SqlClient.SqlException: Cannot open database "Master_Calendar" requested by the login. The login failed.
Login failed for user 'MC_User'.
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)
   at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
   at System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)
   at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnection owningObject)
   at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(String host, String newPassword, Boolean redirectedUserInstance, SqlConnection owningObject, SqlConnectionString connectionOptions, Int64 timerStart)
   at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)
   at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)
   at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)
   at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)
   at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)
   at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
   at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
   at System.Data.SqlClient.SqlConnection.Open()
   at Dea.MasterCalendar.Utilities.DataAccess.d.a()
   at Dea.MasterCalendar.Utilities.DataAccess.d.h(String A_0, SqlParameter[] A_1)
   --- End of inner exception stack trace ---
   at Dea.MasterCalendar.Utilities.DataAccess.d.h(String A_0, SqlParameter[] A_1)
   at Dea.MasterCalendar.Utilities.License.b.f()
   at Dea.MasterCalendar.Web.Pages.Global.Application_BeginRequest(Object sender, EventArgs e)<hr /><b>Additional Information</b><br/>ErrorCaughtBy: Global.asax<br/>DatabaseServer: (local)<br/>Database: Master_Calendar<br/>ClientName: <br/>Product: <br/>SqlStatement: MC_License_GetData<br/>@VersionID: 1<br/>