# Error: your sequences are not the same length **URL:** \ **Category:** Uncategorized\ **Created:** [December 4, 2020, 2:53pm UTC](https://forum.mothur.org/t/error-your-sequences-are-not-the-same-length/20780 "2020-12-04T14:53:06Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![LunaML](https://avatars.discourse-cdn.com/v4/letter/l/e68b1a/32.png) [@LunaML](https://forum.mothur.org/u/LunaML)\ **Post date:** [December 4, 2020, 2:53pm UTC](https://forum.mothur.org/t/error-your-sequences-are-not-the-same-length/20780/1 "2020-12-04T14:53:06Z")
Hi, I have classified my reads with classify.seq() and that seems to have worked well, but when I try to pass my fasta file to dist.seq() to obtain an OTU table, I get the error “your sequences are not the same length, aborting”. I found the same error on this forum, but there was no solution posted. I have 16S Nanopore data, so possibly my error is caused by that? Do I need to align the data before using dist.seq()? Because when I align it to my reference database, and then proceed with classify.seq(), the classification does not work anymore. Best regards, Luna van der Loos ---
**Author:** ![pschloss](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.mothur.org/pschloss/32/4_2.png) [@pschloss](https://forum.mothur.org/u/pschloss)\ **Post date:** [December 10, 2020, 1:45pm UTC](https://forum.mothur.org/t/error-your-sequences-are-not-the-same-length/20780/2 "2020-12-10T13:45:26Z")
Hi - yes, the sequences must be aligned prior to running `dist.seqs`. I’m not sure why `classify.seqs` isn’t working for you. It shouldn’t matter whether the sequences are aligned or not to run `classify.seqs`. I would suggest more or less following the MiSeq SOP instructions. If you’re doing this and still running in to problems, can you post the commands you are running before `classify.seqs` along with the syntax you are using for `classify.seqs`?