AttributeError: 'NoneType' object has no attribute 'Results'

[lucky_lin]

The simulation suddenly encountered this error, even though the same code was used previously without any issues.

import numpy
import s4l_v1.analysis as analysis
import s4l_v1.document as document
import s4l_v1.model as model
import s4l_v1.units as units
from s4l_v1 import ReleaseVersion
from s4l_v1 import Unit

try:
# Define the version to use for default values
ReleaseVersion.set_active(ReleaseVersion.version8_2)

# Creating the analysis pipeline
# Adding a new SimulationExtractor
simulation = document.AllSimulations["0_17_35_29"]
simulation_extractor = simulation.Results()

# Adding a new EmSensorExtractor
em_sensor_extractor = simulation_extractor["Overall Field"]
em_sensor_extractor.FrequencySettings.ExtractedFrequency = u"All"
document.AllAlgorithms.Add(em_sensor_extractor)

# Adding a new CurrentExtractor
inputs = [em_sensor_extractor.Outputs["EM Potential(x,y,z,f0)"], em_sensor_extractor.Outputs["J(x,y,z,f0)"]]
current_extractor = analysis.extractors.CurrentExtractor(inputs=inputs)
current_extractor.IsoSurfacePerCentThreshold = 30.0
current_extractor.UpdateAttributes()
document.AllAlgorithms.Add(current_extractor)

except Exception as exc:
import traceback
traceback.print_exc()
# Reset active version to default
ReleaseVersion.reset()
raise(exc)