problem upgrading from 1.9 to 2.4

I followed the insdtrcution on the upgrades from 1.9 to 2.0, 2.0...  now that after running the upgrade script and starting the project in the 2010, I get an error from the install screen.

•Setup failed: System.InvalidOperationException: Sequence contains more than one element at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source) at System.Data.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__3[TResult](IEnumerable`1 sequence) at System.Data.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable`1 query, Expression queryRoot) at System.Data.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[S](Expression expression) at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression) at System.Linq.Queryable.Single[TSource](IQueryable`1 source) at Nop.Services.Installation.InstallationService.InstallSettings() in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Libraries\Nop.Services\Installation\InstallationService.cs:line 4533 at Nop.Services.Installation.InstallationService.InstallData(String defaultUserEmail, String defaultUserPassword, Boolean installSampleData) in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Libraries\Nop.Services\Installation\InstallationService.cs:line 9409 at Nop.Web.Controllers.InstallController.Index(InstallModel model) in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Presentation\Nop.Web\Controllers\InstallController.cs:line 434

https://www.nopcommerce.com/boards/t/10620/200-beta-install-error-new-rev-existing-db.aspx

Thanks for your reply. I followed that but now I'm getting a different error:

•Setup failed: System.NullReferenceException: Object reference not set to an instance of an object. at Nop.Services.Configuration.SettingService.SetSetting[T](String key, T value, Boolean clearCache) in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Libraries\Nop.Services\Configuration\SettingService.cs:line 154 at CallSite.Target(Closure , CallSite , ISettingService , String , Object , Boolean ) at Nop.Services.Configuration.ConfigurationProvider`1.SaveSettings(TSettings settings) in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Libraries\Nop.Services\Configuration\ConfigurationProvider.cs:line 53 at Nop.Services.Installation.InstallationService.InstallSettings() in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Libraries\Nop.Services\Installation\InstallationService.cs:line 4447 at Nop.Services.Installation.InstallationService.InstallData(String defaultUserEmail, String defaultUserPassword, Boolean installSampleData) in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Libraries\Nop.Services\Installation\InstallationService.cs:line 9409 at Nop.Web.Controllers.InstallController.Index(InstallModel model) in C:\VisualStudioProjects\GASOOnlineStore\GASO_Converted\Presentation\Nop.Web\Controllers\InstallController.cs:line 434

this to me looks like your settings.txt file maybe start a version 2.0 and copy the resultant settings.txt file somewhere you will need this when upgrading from 2.0 through to 2.5

do a google search on some of the error and an answer will come up.

This is how i have managed to fix all my problems upgrading from 1.9 to 2.5

good luck