# Slicer crash without Error message when calling vtkMRMLSequenceNode.GetNthDataNode(-1)

**URL:** <https://discourse.slicer.org/t/slicer-crash-without-error-message-when-calling-vtkmrmlsequencenode-getnthdatanode-1/25043>\
**Category:** Feature requests\
**Tags:** python, module\
**Created:** [September 1, 2022, 2:50pm UTC](https://discourse.slicer.org/t/slicer-crash-without-error-message-when-calling-vtkmrmlsequencenode-getnthdatanode-1/25043 "2022-09-01T14:50:23Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![sunshine](https://avatars.discourse-cdn.com/v4/letter/s/3ec8ea/32.png) [@sunshine](https://discourse.slicer.org/u/sunshine)\
**Post date:** [September 1, 2022, 2:50pm UTC](https://discourse.slicer.org/t/slicer-crash-without-error-message-when-calling-vtkmrmlsequencenode-getnthdatanode-1/25043/1 "2022-09-01T14:50:23Z")

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Operating system: Win10  
Slicer version: 5.1.0-2022-08-16  
Expected behavior: Generate an Error message, instead of crashing without any warning or error  
Actual behavior: Crash directly with no error message

This happens when the input argument of function .GetNthDataNode( int itemNumber \< 0 ).  
The crashing without a hint gives the programmer a hard time debugging.