System.ApplicationException: Sql Exception with error number 201 (Tries=0) ---> System.Data.SqlClient.SqlException: Procedure or function 'yaf_pageload' expects parameter '@BoardUID', which was not supplied.

vid System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)

vid System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)

vid System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)

vid System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)

vid System.Data.SqlClient.SqlDataReader.ConsumeMetaData()

vid System.Data.SqlClient.SqlDataReader.get_MetaData()

vid System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)

vid System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)

vid System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)

vid System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)

vid System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)

vid System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)

vid System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)

vid System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)

vid System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)

vid System.Data.Common.DbDataAdapter.Fill(DataSet dataSet)

vid YAF.Classes.Data.DBAccess.GetDatasetBasic(SqlCommand cmd, Boolean transaction) i C:\sourcefiles\web\VisualCron - web\VisualCron\YAF.Classes\YAF.Classes.Data\DBAccess.cs:rad 311

vid YAF.Classes.Data.DBAccess.GetData(SqlCommand cmd, Boolean transaction) i C:\sourcefiles\web\VisualCron - web\VisualCron\YAF.Classes\YAF.Classes.Data\DBAccess.cs:rad 337

vid YAF.Classes.Data.DB.pageload(Object sessionID, Object boardID, Object userKey, Object ip, Object location, Object browser, Object platform, Object categoryID, Object forumID, Object topicID, Object messageID, Object donttrack) i C:\sourcefiles\web\VisualCron - web\VisualCron\YAF.Classes\YAF.Classes.Data\DB.cs:rad 138

--- Slut på stackspårning för interna undantag ---

vid YAF.Classes.Data.DB.pageload(Object sessionID, Object boardID, Object userKey, Object ip, Object location, Object browser, Object platform, Object categoryID, Object forumID, Object topicID, Object messageID, Object donttrack) i C:\sourcefiles\web\VisualCron - web\VisualCron\YAF.Classes\YAF.Classes.Data\DB.cs:rad 155

vid YAF.Classes.Utils.YafContext.InitUserAndPage() i C:\sourcefiles\web\VisualCron - web\VisualCron\YAF.Classes\YAF.Classes.Utils\Context.cs:rad 844

If yes you always need to Run yaf/install/Default.aspx To Update all the Sql Procedures, then the error will disappear.

Is that a fresh new installation?

This part from your event log is definitively not yaf 1.9.5.5 it must be older.

Then make your you remove the old stuff.

Update all files and run the update installer.

For example the Project from your log YAF.Classes.Utils is removed also YAF.Classes.Core and YAF.Classes.UI. But there are to new projects YAF.Types, YAF.Core and YAF.Utils. The easiest way to load all new files is to load the Main Visual Studio Solution File "yetanotherforum.net-2010"