This is what is in the event log... I see the duplicate key error (no clue how it happened) but not sure what steps to fix it.
LogGUID LogTypeKey LogConfigID LogUserID LogUserName LogPortalID LogPortalName LogCreateDate LogServerName LogProperties LogNotificationPending LogEventID ExceptionHash AssemblyVersion PortalId UserId TabId RawUrl Referrer UserAgent Message StackTrace InnerMessage InnerStackTrace Source
dd5d8e3f-5fed-4ca3-8e77-9f53a13c24d6 PAGE_LOAD_EXCEPTION 6 NULL NULL 0 LCB Paralegal 2016-06-24 14:08:26.633 XDNN01
AbsoluteURL/Default.aspxDefaultDataProviderDotNetNuke.Data.SqlDataProvider, DotNetNukeExceptionGUIDde37173a-f8c7-4eec-892a-d542a93225bb NULL 6142 YKb/SCxKFZ2Z8hrNyAylSQ== 8.0.3 0 -1 58 /login.aspx?ReturnUrl=/&popUp=true
http://www.lcbparalegal.ca/login.aspx?ReturnUrl=/&popUp=true Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36 Violation of UNIQUE KEY constraint 'IX_Users'. Cannot insert duplicate key in object 'dbo.Users'. The duplicate key value is (admin@mydomain.com). Cannot insert duplicate key row in object 'dbo.aspnet_Users' with unique index 'aspnet_Users_Index'. The duplicate key value is (59b6531d-2339-4976-ade0-b7ba8cad61b0, admin@mydomain.com). The statement has been terminated. The statement has been terminated. NULL Violation of UNIQUE KEY constraint 'IX_Users'. Cannot insert duplicate key in object 'dbo.Users'. The duplicate key value is (admin@mydomain.com). Cannot insert duplicate key row in object 'dbo.aspnet_Users' with unique index 'aspnet_Users_Index'. The duplicate key value is (59b6531d-2339-4976-ade0-b7ba8cad61b0, admin@mydomain.com). The statement has been terminated. The statement has been terminated. at System.Data.SqlClient.SqlConnection. (SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, SqlDataReader ds) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean asyncWrite) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at PetaPoco.Database.Execute(String sql, Object[] args) at DotNetNuke.Data.PetaPoco.PetaPocoHelper.ExecuteNonQuery(String connectionString, CommandType type, String sql, Object[] args) at DotNetNuke.Data.DataProvider.ChangeUsername(Int32 userId, String newUsername) at DotNetNuke.Security.Membership.AspNetMembershipProvider.ChangeUsername(Int32 userId, String newUsername) at DotNetNuke.Modules.Admin.Authentication.DNN.Login.OnLoginClick(Object sender, EventArgs e) at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) NULL