# Dwipreproc eddy\_cuda --slspec Unable to open file MultiBandGroups

**URL:** <https://community.mrtrix.org/t/dwipreproc-eddy-cuda-slspec-unable-to-open-file-multibandgroups/1573>\
**Category:** Uncategorized\
**Created:** [April 6, 2018, 6:45pm UTC](https://community.mrtrix.org/t/dwipreproc-eddy-cuda-slspec-unable-to-open-file-multibandgroups/1573 "2018-04-06T18:45:09Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![rsmith](https://community.mrtrix.org/user_avatar/community.mrtrix.org/rsmith/32/2672_2.png) [@rsmith](https://community.mrtrix.org/u/rsmith)\
**Post date:** [April 12, 2018, 1:48am UTC](https://community.mrtrix.org/t/dwipreproc-eddy-cuda-slspec-unable-to-open-file-multibandgroups/1573/4 "2018-04-12T01:48:15Z")

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> `UnicodeDecodeError: ‘utf8’ codec can’t decode byte 0xa0 in position 0: invalid start byte`

Okay, that looks like a similar issue to [Hamed’s recent post](http://community.mrtrix.org/t/dwipreproc-command-error/1574) and the corresponding [GitHub issue](https://github.com/MRtrix3/mrtrix3/issues/953). The _MRtrix3_ Python library is falling over when trying to read the text written to the terminal by `eddy`; what I don’t know is whether or not the data it is failing to decode is healthy feedback or an error message. I’ll see if I can reproduce it.

> How imminent are these going to being available?

I’ve been pushing hard on this; was aiming for the end of the week but there’s likely to be ongoing discussion about [this particular issue](https://github.com/MRtrix3/mrtrix3/pull/1228#issuecomment-380636442). You can see the outstanding issues via the relevant [milestone](https://github.com/MRtrix3/mrtrix3/milestone/4) and [pull request](https://github.com/MRtrix3/mrtrix3/pull/1232) on GitHub.

> In the meantime do you see a workaround? Is it possible to copy `slspec.txt` into the `dwipreproc` temporary directory and ‘restart’ `dwipreproc` from there?

That should be possible. All of the scripts that use the _MRtrix3_ Python scripts have the `-continue` option; it’s quite clunky and doesn’t work in all scenarios, but in this case it should be able to serve that purpose.

Alternatively, if you’re not averse to some version control shenanigans, the development branch that includes the updates to `dwipreproc` described earlier is publicly accessible, so you’re welcome to give it a try (bearing in mind that checking out that branch will come with a large batch of other changes throughout the entire software).

Rob

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