Help me solve this question:Invalid value for key 'integrated security'

[ArgumentException: Invalid value for key 'integrated security'.]
  System.Data.Common.DbConnectionOptions.ConvertValueToIntegratedSecurityInternal(String stringValue) +1419882
  System.Data.Common.DbConnectionOptions.ConvertValueToIntegratedSecurity() +5025005
  System.Data.SqlClient.SqlConnectionString..ctor(String connectionString) +104
  System.Data.SqlClient.SqlConnectionFactory.CreateConnectionOptions(String connectionString, DbConnectionOptions previous) +24
  System.Data.ProviderBase.DbConnectionFactory.GetConnectionPoolGroup(String connectionString, DbConnectionPoolGroupOptions poolOptions, DbConnectionOptions& userConnectionOptions) +150
  System.Data.SqlClient.SqlConnection.ConnectionString_Set(String value) +59
  System.Data.SqlClient.SqlConnection.set_ConnectionString(String value) +4
  System.Data.SqlClient.SqlConnection..ctor(String connectionString) +26
  System.Web.DataAccess.SqlConnectionHolder..ctor(String connectionString) +54

[ArgumentException: An error occurred while attempting to initialize a System.Data.SqlClient.SqlConnection object. The value that was provided for the connection string may be wrong, or it may contain an invalid syntax.
Parameter name: connectionString]
  System.Web.DataAccess.SqlConnectionHolder..ctor(String connectionString) +136
  System.Web.DataAccess.SqlConnectionHelper.GetConnection(String connectionString, Boolean revertImpersonation) +119
  System.Web.Security.SqlMembershipProvider.GetPasswordWithFormat(String username, Boolean updateLastLoginActivityDate, Int32& status, String& password, Int32& passwordFormat, String& passwordSalt, Int32& failedPasswordAttemptCount, Int32& failedPasswordAnswerAttemptCount, Boolean& isApproved, DateTime& lastLoginDate, DateTime& lastActivityDate) +827
  System.Web.Security.SqlMembershipProvider.CheckPassword(String username, String password, Boolean updateLastLoginActivityDate, Boolean failIfNotApproved, String& salt, Int32& passwordFormat) +105
  System.Web.Security.SqlMembershipProvider.ValidateUser(String username, String password) +106
  System.Web.UI.WebControls.Login.AuthenticateUsingMembershipProvider(AuthenticateEventArgs e) +60
  System.Web.UI.WebControls.Login.OnAuthenticate(AuthenticateEventArgs e) +129
  System.Web.UI.WebControls.Login.AttemptLogin() +127
  System.Web.UI.WebControls.Login.OnBubbleEvent(Object source, EventArgs e) +101
  System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +37
  System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) +125
  System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +167
  System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
  System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
  System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
  System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5563