Can not segment on master volume

Hi,
In SegmentEditor module, after the MRI data was loaded as scalar volume and create a new segmentation, the Threshold and Level tracing can not be used correctly. The log messages showed that: File “/Volumes/Dashboards/Stable/Slicer-4100-build/Slicer-build/lib/Slicer-4.10/qt-scripted-modules/SegmentEditorEffects/SegmentEditorLevelTracingEffect.py”, line 66, in processInteractionEvents

AttributeError: ‘module’ object has no attribute ‘qSlicerSegmentEditorAbstractEffect’ and strong text.
What is the reason about this and how to solve this problem?
Thanks

It looks like you have a very old version of Slicer. Please try again with the current release (5.2.2 from download.slicer.org) and let us know how it goes.