Slicer 5.11.0 crashes immediately when switching to nnInteractive module

Support
1

Using Slicer 5.11.0 on 2026 Macbook pro, M5 Pro chip.

After installing the nnInteractive extension and restarting Slicer, when I switch to the nnInteractive module, it tries to install some dependencies. Almost immediately, Slicer quits.

No issue when performing the same steps in Slicer 5.10.0.

Perhaps related to recent version compatibility changes to nnUnet? nnUNet fails with ModuleNotFoundError: No module named 'torchvision.ops' - #5 by lassoan

2

nnInteractive extension barely installs any dependencies, so I’m surprised that it runs into issues. It just needs requests_toolbelt, scikit-image, and (for testing) matplotlib. Could you please install these manually, for example: pip_install("requests_toolbelt"), and see if any of them causing trouble?

3

Thanks for the suggestion. I installed requests_toolbelt, scikit-image and matplotlib manually through the Python console (e.g. slicer.util.pip_install("requests_toolbelt")) and that worked fine. In fact, when I switched back to nnInteractive module, it didn’t try to install dependencies and didn’t crash at all. And the module worked perfectly fine.

This is what Codex found regarding the crash

My current suspicion is that this is a macOS/Slicer-preview startup UI issue in nnInteractive, not a missing requests_toolbelt import.

In the extension code, SlicerNNInteractiveWidget.setup() immediately calls self.install_dependencies() before the rest of the module UI is initialized. That dependency-install path can create a modal Qt progress dialog via slicer.util.createProgressDialog(...).

From the crash report, the failure happens while Slicer is switching into the module and building its widget. The backtrace goes through:

qSlicerAbstractCoreModule::widgetRepresentation()
qSlicerModulePanel::setModule(QString const&)
PythonQt...
QDialog::setVisible(bool)
QWidgetPrivate::setVisible(bool)
QWidget::create(...)
QWindowPrivate::create(...)
-[NSWindow initWithContentRect:styleMask:backing:defer:]
-[NSPanel _initContent:styleMask:backing:defer:contentView:]
Then AppKit raises an Objective-C exception and Slicer aborts with SIGABRT.

So the crash appears to be happening in the module’s dependency-install/dialog creation path during startup, rather than later in the server/networking code.