# Extract block indices

**URL:** https://discourse.paraview.org/t/extract-block-indices/785
**Category:** ParaView Support
**Created:** [October 23, 2018, 9:03pm UTC](https://discourse.paraview.org/t/extract-block-indices/785 "2018-10-23T21:03:53Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![nck](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/n/94ad74/32.png) [@nck](https://discourse.paraview.org/u/nck)
#### Post date: [October 23, 2018, 9:03pm UTC](https://discourse.paraview.org/t/extract-block-indices/785/1 "2018-10-23T21:03:53Z")

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I downloaded the latest version 5.6.0 and used the Filter-\>Alphabetical-\>Extract Block to show the surface reference numbers of a mesh. Instead of listing surface indices in number as in previous versions of ParaView, all entries show “Unstructured Grid”. How can I get the block indices? I

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### Author: ![wascott](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/w/8e8cbc/32.png) [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [October 23, 2018, 9:43pm UTC](https://discourse.paraview.org/t/extract-block-indices/785/2 "2018-10-23T21:43:43Z")

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I just looked at 5.4.1 and 5.5.2, and 5.6.0 rc2, and they are identical. Could you please give us a screenshot of the difference between versions, and possibly a dataset that shows issues?

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### Author: ![nck](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/n/94ad74/32.png) [@nck](https://discourse.paraview.org/u/nck)
#### Post date: [October 23, 2018, 10:33pm UTC](https://discourse.paraview.org/t/extract-block-indices/785/3 "2018-10-23T22:33:39Z")

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Here are the screenshots using ParaView 4.0.1 and 5.6.0. Also uploaded the mesh file in NetCDF format. I use “SLAC plugin” to load the mesh file in ParaView.

 ![1](https://discourse.paraview.org/uploads/default/original/1X/5d6c12cbd3e25e79f503d18dd616b549cc9106ae.png)

 ![Untitled](https://discourse.paraview.org/uploads/default/original/1X/15b520dcec167f6913ce7bb573a94d6a7b89af64.png)

[test.ncdf](https://discourse.paraview.org/uploads/default/original/1X/0d33a6bfb84f6d07e96077f932e709557e3a1b75.ncdf) (86.0 KB)

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### Author: ![wascott](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/w/8e8cbc/32.png) [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [October 24, 2018, 12:01am UTC](https://discourse.paraview.org/t/extract-block-indices/785/4 "2018-10-24T00:01:20Z")

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Yep, I replicated the issue. It’s actually a bug in the reader, not the Extract Blocks filter. I wrote it up here: [https://gitlab.kitware.com/paraview/paraview/issues/18564](https://gitlab.kitware.com/paraview/paraview/issues/18564)