I upgraded from 4.5.5 to 4.8.0, everything went ok but I am facing some problems.

1. Event Viewer is not working, I get the following error message when trying to access it :

Error: Event Viewer is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. The statement has been terminated. ---> System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. 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, CommandType commandType, String commandText) at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteNonQuery(String connectionString, String spName, Object[] parameterValues) at DotNetNuke.Services.Log.EventLog.DBLoggingProvider.Data.SqlDataProvider.PurgeLog() at DotNetNuke.Services.Log.EventLog.DBLoggingProvider.DBLoggingProvider.PurgeLogBuffer() at DotNetNuke.Services.Log.EventLog.LogController.PurgeLogBuffer() at DotNetNuke.Modules.Admin.Log.LogViewer.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---

2. Randomly, cannot delete or add pages and modules.

3. Cannot add or delete vendors under host or admin menu.

4. None of the modules are editable anymore, I cannot access their settings.  Cannot add or delete a module from any page on the website.

Any help appreciated. Thanks