I get this error when I try to updates site entries to my install of DNN. Any help would be greatly appreciated!

Error: Site Settings is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Cannot insert the value NULL into column 'DefaultLanguage', table 'admin_mssql0ae4513c524b140dcd33a176d39f1bd0.usr2de69d4484e04be279be3e1effe6761d.Portals'; column does not allow nulls. UPDATE fails. The statement has been terminated. ---> System.Data.SqlClient.SqlException: Cannot insert the value NULL into column 'DefaultLanguage', table 'admin_mssql0ae4513c524b140dcd33a176d39f1bd0.usr2de69d4484e04be279be3e1effe6761d.Portals'; column does not allow nulls. UPDATE fails. The statement has been terminated. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) 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.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) at System.Data.SqlClient.SqlCommand.ExecuteNonQuery() at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(SqlConnection connection, CommandType commandType, String commandText, SqlParameter[] commandParameters) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, CommandType commandType, String commandText, SqlParameter[] commandParameters) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, String spName, Object[] parameterValues) at DotNetNuke.Data.SqlDataProvider.UpdatePortalInfo(Int32 PortalId, String PortalName, String LogoFile, String FooterText, DateTime ExpiryDate, Int32 UserRegistration, Int32 BannerAdvertising, String Currency, Int32 AdministratorId, Double HostFee, Double HostSpace, Int32 PageQuota, Int32 UserQuota, String PaymentProcessor, String ProcessorUserId, String ProcessorPassword, String Description, String KeyWords, String BackgroundFile, Int32 SiteLogHistory, Int32 SplashTabId, Int32 HomeTabId, Int32 LoginTabId, Int32 UserTabId, String DefaultLanguage, Int32 TimeZoneOffset, String HomeDirectory, Int32 lastModifiedByUserID) at DotNetNuke.Entities.Portals.PortalController.UpdatePortalInfo(Int32 PortalId, String PortalName, String LogoFile, String FooterText, DateTime ExpiryDate, Int32 UserRegistration, Int32 BannerAdvertising, String Currency, Int32 AdministratorId, Double HostFee, Double HostSpace, Int32 PageQuota, Int32 UserQuota, String PaymentProcessor, String ProcessorUserId, String ProcessorPassword, String Description, String KeyWords, String BackgroundFile, Int32 SiteLogHistory, Int32 SplashTabId, Int32 HomeTabId, Int32 LoginTabId, Int32 UserTabId, String DefaultLanguage, Int32 TimeZoneOffset, String HomeDirectory) at DotNetNuke.Modules.Admin.Portals.SiteSettings.cmdUpdate_Click(Object sender, EventArgs e) --- End of inner exception stack trace ---

Thanks for the information! 

Hmmm... Gemini says that the issue should be fixed in 5.1.4, but I can't find an implementation of that fix in the code base.

In my first post, I linked to the Gemini issue.  The second comment listed (from Erik) has a script that you can run from the Host->SQL page, which should fix the issue for you.

Hope that helps,