# Qiime demux summarize error with NextSeq data

**URL:** <https://forum.qiime2.org/t/qiime-demux-summarize-error-with-nextseq-data/3339>\
**Category:** User Support\
**Tags:** pending-development, import, summarize\
**Created:** [March 7, 2018, 3:03pm UTC](https://forum.qiime2.org/t/qiime-demux-summarize-error-with-nextseq-data/3339 "2018-03-07T15:03:48Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![thermokarst](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/t/8e7dd6/32.png) [@thermokarst](https://forum.qiime2.org/u/thermokarst)\
**Post date:** [March 7, 2018, 9:33pm UTC](https://forum.qiime2.org/t/qiime-demux-summarize-error-with-nextseq-data/3339/3 "2018-03-07T21:33:43Z")

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Hi @ylor!

Congrats, you found a bug! 🐛 🐌 I [opened an issue](https://github.com/qiime2/q2-types/issues/172) for tracking a fix for this.

The good news is that you have some other options available to you!

* * *

> [@ylor](#):
>
> Can someone clarify the difference between SingleLane and LaneLess for CasavaOneEight data import format?

The [CASAVA 1.8 format](https://docs.qiime2.org/2018.2/tutorials/importing/#casava-1-8-paired-end-demultiplexed-fastq) expects demuxed reads to have filenames that look like this:

`L2S357_15_L001_R1_001.fastq.gz`

> The underscore-separated fields in this file name are the sample identifier, the barcode sequence or a barcode identifier, the lane number, the read number, and the set number.

The `CasavaOneEightLanelessPerSampleDirFmt` is a variant of that format that we have seen floating around, it is the exact same as CASAVA 1.8, except it is missing the lane in the filename:

`L2S357_15_R1_001.fastq.gz`

* * *

> [@ylor](#):
>
> Should I use a completely different data import format?

Check out the [fastq manifest format](https://docs.qiime2.org/2018.2/tutorials/importing/#fastq-manifest-formats), you should be able to create a manifest for these files and import!

Just curious, how did you stumble across the `CasavaOneEightLanelessPerSampleDirFmt` format? We haven't really documented it or advertised it, which is why there isn't much info floating around about it. Anyway, thanks, and keep us posted! 🦖

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