I'm adding a page in a DNN 7.0 site, it was updated from 5.6.3.
When I add the page I get this error:

Error: is currently unavailable. DotNetNuke.Services.Exceptions.ModuleLoadException: Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, , >= or when the subquery is used as an expression. The statement has been terminated. ---> System.Data.SqlClient.SqlException: Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, , >= or when the subquery is used as an expression. The statement has been terminated. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction) at System.Data.SqlClient.SqlInternalConnection.OnError(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.SqlDataReader.TryConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() 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) 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.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at System.Data.SqlClient.SqlCommand.ExecuteScalar() at PetaPoco.Database.ExecuteScalar[T](String sql, Object[] args) at DotNetNuke.Data.PetaPoco.PetaPocoHelper.ExecuteScalar[T](String connectionString, CommandType type, String sql, Object[] args) at DotNetNuke.Data.SqlDataProvider.ExecuteScalar[T](String procedureName, Object[] commandParameters) at DotNetNuke.Data.DataProvider.AddTabAfter(TabInfo tab, Int32 afterTabId, Int32 createdByUserID) at DotNetNuke.Entities.Tabs.TabController.AddTabInternal(TabInfo tab, Int32 afterTabId, Int32 beforeTabId, Boolean includeAllTabsModules) at DotNetNuke.Entities.Tabs.TabController.AddTabAfter(TabInfo tab, Int32 afterTabId) at DotNetNuke.Modules.Admin.Tabs.ManageTabs.SaveTabData(String strAction) at DotNetNuke.Modules.Admin.Tabs.ManageTabs.cmdUpdate_Click(Object Sender, EventArgs e) --- End of inner exception stack trace ---

Any idea what's going on? or a fix?