Plot rendering error: 'NoneType' object has no attribute 'dpi'; metadata = {'Entries': 2, 'Name': 'OccupancyDist-10', 'Overflow': 38398.0, 'Type': 'Histo1d', 'Underflow': 115200.0, 'x': {'AxisTitle': 'Occupancy', 'Bins': 49, 'High': 49.5, 'Low': 0.5}, 'y': {'AxisTitle': 'Number of Pixels'}, 'z': {'AxisTitle': 'z'}}