# Dask is crashing: ImportError: /lib64/libstdc++.so.6: version \`GLIBCXX\_3.4.29' not found

**URL:** <https://forum.access-hive.org.au/t/dask-is-crashing-importerror-lib64-libstdc-so-6-version-glibcxx-3-4-29-not-found/5799>\
**Category:** Technical\
**Tags:** help, dask, are, jupyterlab, unresolved\
**Created:** [20 January 2026 06:14 UTC](https://forum.access-hive.org.au/t/dask-is-crashing-importerror-lib64-libstdc-so-6-version-glibcxx-3-4-29-not-found/5799 "2026-01-20T06:14:35Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![dougiesquire](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.access-hive.org.au/dougiesquire/32/16_2.png) [@dougiesquire](https://forum.access-hive.org.au/u/dougiesquire)\
**Post date:** [20 January 2026 21:58 UTC](https://forum.access-hive.org.au/t/dask-is-crashing-importerror-lib64-libstdc-so-6-version-glibcxx-3-4-29-not-found/5799/2 "2026-01-20T21:58:42Z")

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Hi @raslekar

I haven’t been able to reproduce your issue exactly (using `conda/analysis3-26.01`), but as a general tip you should use `threads_per_worker=1` when opening netcdf data in parallel:

```diff
- cluster = LocalCluster(
- n_workers=7,
- threads_per_worker=4
- )
+ cluster = LocalCluster(threads_per_worker=1)

```

See [here](https://forum.access-hive.org.au/t/netcdf-not-a-valid-id-errors/389/20) for details.

If you’re still having issues after changing this, could you please provide the exact version of the `conda/analysis3` environment you are using? You can find it in the top right corner of the notebook:  
 ![Screenshot 2026-01-21 at 8.57.26 am](https://us1.discourse-cdn.com/flex020/uploads/access1/original/2X/7/739167b21710ab5295b30207ada31b2c8b9bdd95.png)

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