The crash happens in mitk::SliceNavigationController::GetSelectedTimeStep() as m_Time (mitk::Stepper::Pointer) is accessed while it is a nullptr. The events that lead to this situation are that the mitk::ToolManager notifies QmitkSlicesInterpolator via OnToolManagerWorkingDataModified(). This method calls SetCurrentContourListID() in turn, which executes the crashing line of code:

const auto timePoint = m_LastSNC->GetSelectedTimePoint()
GetSelectedTimeStep() GetTime() m_Time->GetPos()

The interesting part here is that m_Time of mitk::BaseController is not supposed to be nullptr in particular as m_Slice is a valid stepper. My first guess is that a partly deconstructed controller is triggered here.

Shortcut to reproduce the crash:

• Start the Workbench
• If not already opened, open the Segmentation View
• Close the project or close the Standard Display
• Load any segmentation

Reason:

• In QmitkSegmentationView::RenderWindowPartActivated(), QmitkSlicesInterpolator::Initialize() is called with a list of raw pointers to mitk::SliceNavigationControllers, which in turn saves these raw pointers
• When the Standard Display is closed, QmitkSegmentationView::RenderWindowPartDeactivated() does not call QmitkSlicesInterpolator::Uninitialize()
• QmitkSlicesInterpolator still holds raw pointers to the controllers that were destructed when the StandardDisplay was closed, which causes the crash when accessed later on