# Error execcting a command from the tutorial

**URL:** <https://fenicsproject.discourse.group/t/error-execcting-a-command-from-the-tutorial/8787>\
**Category:** dolfinx\
**Created:** [July 15, 2022, 10:18am UTC](https://fenicsproject.discourse.group/t/error-execcting-a-command-from-the-tutorial/8787 "2022-07-15T10:18:40Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![bhaveshshrimali](https://yyz2.discourse-cdn.com/free1/user_avatar/fenicsproject.discourse.group/bhaveshshrimali/32/124_2.png) [@bhaveshshrimali](https://fenicsproject.discourse.group/u/bhaveshshrimali)\
**Post date:** [July 15, 2022, 11:51am UTC](https://fenicsproject.discourse.group/t/error-execcting-a-command-from-the-tutorial/8787/2 "2022-07-15T11:51:36Z")

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Hi Xavier,

The tutorial is based of

```auto
DOLFINx version: 0.4.2.0 based on GIT commit: b983596ace0842230a442e10e49ffd4f27c34419 of https://github.com/FEniCS/dolfinx/

```

You can either upgrade to the latest version or try to see the [corresponding tutorial under a previous commit](https://github.com/jorgensd/dolfinx-tutorial/blob/afece5957caf1515940d94c3a64728b8f3a0750a/chapter1/fundamentals_code.ipynb),

Most likely this should be

```python
boundary_facets = numpy.flatnonzero(mesh.compute_boundary_facets(domain.topology))

```

but I’d have to run this on a previous version to check.

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_[View the full topic](https://fenicsproject.discourse.group/t/error-execcting-a-command-from-the-tutorial/8787)._