Just upgraded my 3.3.4 site to 4.5.3 and am getting the error below, any ideas?

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 ---

Thank you for your quick reply Sebastian. It appears that the problems lies with my virtual test server......

Thanks again!

What's the limit of entries. I had like 70k and gave me errors.

Erased about 60k and still gave me errors (I had around 10k left)

Then I deleted ALL of them and now I can use them. So what's the limit?