# Unable to open RT file generated by Slicer

**URL:** <https://discourse.slicer.org/t/unable-to-open-rt-file-generated-by-slicer/13380>\
**Category:** Support\
**Created:** [September 7, 2020, 9:54pm UTC](https://discourse.slicer.org/t/unable-to-open-rt-file-generated-by-slicer/13380 "2020-09-07T21:54:06Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Gabriel\_T](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/gabriel_t/32/4222_2.png) [@Gabriel\_T](https://discourse.slicer.org/u/Gabriel_T)\
**Post date:** [September 7, 2020, 9:54pm UTC](https://discourse.slicer.org/t/unable-to-open-rt-file-generated-by-slicer/13380/1 "2020-09-07T21:54:06Z")

</div>

I loaded two nrrd volumes, one has the CT volume , the other has a binary segmentation mask. I am able to load and view them without any problem.  
But when I try to save it by exporting to RTseries, it generates the dicom files for each slice and a single RTS dicom file. But when I try to load this directory it tries to load each slice as individual files along with the RTS like in the below screenshot

 ![RTSload](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/2/f21645f9b6b8dae39c729bc70fefbc6a4d6c44c0.png)

When I hit OK it loads all the slices as individual slices (is there any way it can be loaded as a single volume ?) but it gives a big error when it tries to load the rts file  
vtkITKArchetypeImageSeriesReader::ExecuteInformation: Cannot open C:/Users/gabri/Desktop/2/rtss\_1.2.826.0.1.3680043.8.274.1.1.3528944502.44294.5368913286.4316.dcm. ITK exception info: error in unknown: Could not create IO object for reading file C:/Users/gabri/Desktop/2/rtss\_1.2.826.0.1.3680043.8.274.1.1.3528944502.44294.5368913286.4316.dcm  
Tried to create one of the following:  
BMPImageIO  
BioRadImageIO  
DCMTKImageIO  
GDCMImageIO  
GiplImageIO …

---

<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 8, 2020, 1:44am UTC](https://discourse.slicer.org/t/unable-to-open-rt-file-generated-by-slicer/13380/2 "2020-09-08T01:44:46Z")

</div>

Some images may be loaded using “Add data” window, but in generatl you need to open DICOM files using DICOM module.

I would recommend to use the latest Slicer Preview Release, as it has many DICOM support improvements.