DADA2 occurred error for only one sample

like this, and this is the code i run

qiime dada2 denoise-paired \
  --i-demultiplexed-seqs paired-end-demux.qza \
  --p-trim-left-f 0 \
  --p-trim-left-r 0 \
  --p-trunc-len-f 250 \
  --p-trunc-len-r 250 \
  --o-table table.qza \
  --o-representative-sequences rep-seqs.qza \
  --o-denoising-stats denoising-stats.qza \
  --p-n-threads 0

and the QC result:

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sequence has a okay result with FLASH and PEAR


and this is the result ,this first one is the sample i failed
image

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and when i did join-read, the same question occurred.i don't know why there are such error,but the

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Good to hear from you, Rick,

Looks like reads are not pairing consistently…

Try triming that forward read a little sooner, say 240 or 230. That should still give you 40 or 30 bp of overlap.

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