# Error message in the OHIF Viewer

**URL:** <https://discourse.canceridc.dev/t/error-message-in-the-ohif-viewer/149>\
**Category:** Support\
**Tags:** bug\
**Created:** [March 27, 2021, 12:16am UTC](https://discourse.canceridc.dev/t/error-message-in-the-ohif-viewer/149 "2021-03-27T00:16:03Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![giemmecci](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.canceridc.dev/giemmecci/32/71_2.png) [@giemmecci](https://discourse.canceridc.dev/u/giemmecci)\
**Post date:** [March 27, 2021, 12:16am UTC](https://discourse.canceridc.dev/t/error-message-in-the-ohif-viewer/149/1 "2021-03-27T00:16:03Z")

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Hi,  
the OHIF viewer is giving me an error message saying:

“Error loading derived display set: Cannot read property ‘SegmentIdentificationSequence’ of undefined”

It originally appeared when reading any of the LIDC-IDRI dataset case; I’ve tried another dataset (QIN-HEADNECK) and the error persists.

Here is the debug info:

```
Enter the description of your problem here: 

============= SESSION INFO =============

== App ==
version	4.8.11

== Extensions Versions ==
generic-viewer-commands	4.8.11
cornerstone	2.10.2
vtk	1.10.5
html	1.3.2
microscopy	0.51.4
pdf	1.0.6
com.ohif.dicom-segmentation	0.5.3
rt	0.6.5
dicom-p10-downloader	0.1.6
dicom-tag-browser	undefined

== Browser Info ==
name chrome
os Mac OS
type browser
version 89.0.4389

== URL ==
URL https://viewer.imaging.datacommons.cancer.gov/viewer/1.3.6.1.4.1.14519.5.2.1.6279.6001.298806137288633453246975630178

== Viewport Layout ==
Rows	1
Columns	1

== Viewports ==
[0,0]	1.3.6.1.4.1.14519.5.2.1.6279.6001.179049373636438705059720603192

```

Thanks!

 ![Screen Shot 2021-03-26 at 7.03.14 PM](https://us1.discourse-cdn.com/flex015/uploads/canceridc/original/1X/f5be85268fccec90aa4db48059982dc2b7d6280c.jpeg) ![Screen Shot 2021-03-26 at 7.07.59 PM](https://us1.discourse-cdn.com/flex015/uploads/canceridc/original/1X/0657c2503ccb105a291ac4daaa7942ca10c58989.jpeg)

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**Author:** ![fedorov](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.canceridc.dev/fedorov/32/3_2.png) [@fedorov](https://discourse.canceridc.dev/u/fedorov)\
**Post date:** [March 27, 2021, 2:06am UTC](https://discourse.canceridc.dev/t/error-message-in-the-ohif-viewer/149/2 "2021-03-27T02:06:06Z")

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Yes, this is unfortunately a known issue that slipped through our testing. It should be fixed in a matter of days, I hope.

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**Author:** ![fedorov](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.canceridc.dev/fedorov/32/3_2.png) [@fedorov](https://discourse.canceridc.dev/u/fedorov)\
**Post date:** [April 7, 2021, 10:09pm UTC](https://discourse.canceridc.dev/t/error-message-in-the-ohif-viewer/149/3 "2021-04-07T22:09:06Z")

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@giemmecci I admit I don’t know exactly when the production viewer was updated, but segmentation visualization is working now. Please let us know if you see problems.

---

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**Author:** ![giemmecci](https://sea1.discourse-cdn.com/flex015/user_avatar/discourse.canceridc.dev/giemmecci/32/71_2.png) [@giemmecci](https://discourse.canceridc.dev/u/giemmecci)\
**Post date:** [April 10, 2021, 9:24pm UTC](https://discourse.canceridc.dev/t/error-message-in-the-ohif-viewer/149/4 "2021-04-10T21:24:26Z")

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Yes! I can confirm the error messages are gone, thank you!