# Demux summarize error: CRC check failed
**URL:** https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228
**Category:** User Support
**Tags:** dada2, import
**Created:** [February 27, 2018, 10:30pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228 "2018-02-27T22:30:35Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Masha\_T](https://forum.qiime2.org/u/Masha_T)
#### Post date: [February 27, 2018, 10:30pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/1 "2018-02-27T22:30:35Z")
Hello,
I imported my paired end demultiplexed data using a manifest file, and am now ready to denoise with DADA2. However, when I run demux summarize to visualize my sequence quality, I get an error:
qiime demux summarize \
--i-data paired-end-demux.qza
--o-visualization paired-end-demux.qzv
Plugin error from demux:
CRC check failed 0x80fec6e9 != 0x425d426c
Debug info has been saved to /var/folders/x6/sl6dpg0156q050yy\_wm4rjb00000gn/T/qiime2-q2cli-err-gf16id1f.log
Here is the contents of the log file:
Traceback (most recent call last):
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/site-packages/q2cli/commands.py", line 246, in **call**
results = action(\*\*arguments)
File "", line 2, in summarize
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/site-packages/qiime2/sdk/action.py", line 228, in bound\_callable
output\_types, provenance)
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/site-packages/qiime2/sdk/action.py", line 424, in _callable\_executor_
ret\_val = self.\_callable(output\_dir=temp\_dir, \*\*view\_args)
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/site-packages/q2\_demux/\_summarize/\_visualizer.py", line 117, in summarize
for seq in \_read\_fastq\_seqs(file):
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/site-packages/q2\_demux/\_demux.py", line 34, in \_read\_fastq\_seqs
for seq\_header, seq, qual\_header, qual in itertools.zip\_longest(\*[fh] \* 4):
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/gzip.py", line 287, in read1
return self.\_buffer.read1(size)
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/\_compression.py", line 68, in readinto
data = self.read(len(byte\_view))
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/gzip.py", line 452, in read
self.\_read\_eof()
File "/Users/mashataguer/miniconda2/envs/qiime2-2018.2/lib/python3.5/gzip.py", line 499, in \_read\_eof
hex(self.\_crc)))
OSError: CRC check failed 0x80fec6e9 != 0x425d426c
Also, I don't know what version of illumina my sequencing facility used, so I am assuming 33 and used that for importing my sequences. I tried 64 just in case too and got an error "Decoded Phred score is out of range [0, 62]." So I'm assuming the import was successful with phred33.
Does anyone have any ideas what's going on? This is my first time using QIIME2, so maybe I am missing something obvious!
Thanks,
Masha
---
### Author:  [@ebolyen](https://forum.qiime2.org/u/ebolyen)
#### Post date: [February 27, 2018, 10:35pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/2 "2018-02-27T22:35:17Z")
Hi @Masha_T,
> [@Masha\_T](#):
>
> CRC check failed 0x80fec6e9 != 0x425d426c
That CRC error means that some of the data in your original file is missing. That happens with network interruptions pretty often. If you were to download/fetch your fastq files again and re-import the problem should go away.
> [@Masha\_T](#):
>
> Also, I don’t know what version of illumina my sequencing facility used, so I am assuming 33 and used that for importing my sequences. I tried 64 just in case too and got an error “Decoded Phred score is out of range [0, 62].” So I’m assuming the import was successful with phred33.
Yup! Phred 33 is the modern offset. Only very old machines will use 64 as the offset.
---
### Author:  [@cjweiss](https://forum.qiime2.org/u/cjweiss)
#### Post date: [March 5, 2018, 2:19pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/3 "2018-03-05T14:19:04Z")
I am getting a similar error:
CRC check failed 0x88b1f != 0x9f6e909
I have tried to re-import the data as suggested in this thread, but got the same error again when I tried demux summarize. Could I be missing something else?
Thanks!
Carla
---
### Author:  [@Nicholas\_Bokulich](https://forum.qiime2.org/u/Nicholas_Bokulich)
#### Post date: [March 5, 2018, 2:22pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/4 "2018-03-05T14:22:05Z")
---
### Author:  [@ebolyen](https://forum.qiime2.org/u/ebolyen)
#### Post date: [March 5, 2018, 10:18pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/5 "2018-03-05T22:18:00Z")
Hi @cjweiss,
> [@cjweiss](#):
>
> I have tried to re-import the data as suggested in this thread, but got the same error again when I tried demux summarize. Could I be missing something else?
The issue isn't the import per-se, rather it is the original fastq files that you are importing which are corrupt.
If you get them again from your sequencing center, network drive, however it was you got them originally, you should be able to re-download/transfer to get the complete file (rather than the incomplete file that you have now).
---
### Author:  [@ebolyen](https://forum.qiime2.org/u/ebolyen)
#### Post date: [March 5, 2018, 10:18pm UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/6 "2018-03-05T22:18:02Z")
---
### Author:  [@system](https://forum.qiime2.org/u/system)
#### Post date: [April 6, 2018, 4:18am UTC](https://forum.qiime2.org/t/demux-summarize-error-crc-check-failed/3228/7 "2018-04-06T04:18:02Z")
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