ResultsViewer might be choking on the "HVAC Sizing Simulations," try setting Do HVAC Sizing Simulation for Sizing Periods to No in SimulationControl and see if the problem goes away. If you want to use coincident plant sizing then may need to switch to a different plotting tool. Try with Run Simulation for Sizing Periods set to No as well. Also old translated example files don't usually have a name in the RunPeriod object and ResultsViewer seems to work better if you enter a name.
The annual tabular summary reports show the number of hours that were used in the annual summations at the top of the table report file. If that says 8760 hours, you can be sure the tabluar reports are for the one year. If you are using raw meter reports at the RunPeriod frequency, then you can verify their timeframe by checking that the values agree with the annual summary tables.