# Failed to save a scene to external ExFAT usb volume on MacOS

**URL:** <https://discourse.slicer.org/t/failed-to-save-a-scene-to-external-exfat-usb-volume-on-macos/31835>\
**Category:** Support\
**Tags:** save\
**Created:** [September 21, 2023, 8:19pm UTC](https://discourse.slicer.org/t/failed-to-save-a-scene-to-external-exfat-usb-volume-on-macos/31835 "2023-09-21T20:19:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![DennisEx81](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dennisex81/32/67614_2.png) [@DennisEx81](https://discourse.slicer.org/u/DennisEx81)\
**Post date:** [September 21, 2023, 8:19pm UTC](https://discourse.slicer.org/t/failed-to-save-a-scene-to-external-exfat-usb-volume-on-macos/31835/1 "2023-09-21T20:19:37Z")

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Hello,

Version 5.4.0, I was not able to save a scene successfully to an external usb volume on MacOS (works on windows though). Error message below,

```auto
vtkMRMLVolumeArchetypeStorageNode::WriteDataInternal: Error renaming file to /Volumes/USB1/test1/._t1.nii.gz, renameReturn = -1

```

```auto
bool qSlicerCoreIOManager::saveNodes(qSlicerIO::IOFileType, const qSlicerIO::IOProperties &, vtkMRMLMessageCollection *, vtkMRMLScene *) error: Saving failed with all writers found for file "/Volumes/USB1/test1/t1.nii.gz" of type "VolumeFile"
void qSlicerSaveDataDialogPrivate::updateStatusIconFromMessageCollection(int, vtkMRMLMessageCollection *, bool) Data save error: "- Error: Error renaming file to /Volumes/USB1/test1/._t1.nii.gz, renameReturn = -1\n- Error: Cannot write data file: /Volumes/USB1/test1/t1.nii.gz.\n"

```

Anyone knows why?

Thank you!  
Dennis

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [September 21, 2023, 8:21pm UTC](https://discourse.slicer.org/t/failed-to-save-a-scene-to-external-exfat-usb-volume-on-macos/31835/2 "2023-09-21T20:21:19Z")

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By default, node names are used as file names. It seems that your node name has some special characters or starts or ends with a space, etc. that is not a valid filename on the file system you are trying to save. I would recommend to rename the node.

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<div class="post-metadata">

**Author:** ![DennisEx81](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/dennisex81/32/67614_2.png) [@DennisEx81](https://discourse.slicer.org/u/DennisEx81)\
**Post date:** [September 21, 2023, 8:33pm UTC](https://discourse.slicer.org/t/failed-to-save-a-scene-to-external-exfat-usb-volume-on-macos/31835/3 "2023-09-21T20:33:08Z")

</div>

I simply named the node as t1 but the error message shows it somehow tried to rename/save the file to .\_t1 or going through this process. It only happened in macos but worked fine in windows.

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<div class="post-metadata">

**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [September 21, 2023, 8:55pm UTC](https://discourse.slicer.org/t/failed-to-save-a-scene-to-external-exfat-usb-volume-on-macos/31835/4 "2023-09-21T20:55:25Z")

</div>

Make sure the node name does not start or end with a space. It may be hard to see that when the node name is displayed, but more visible when you are editing the node name.