Humann (v3.9) returning 100% unaligned reads on demo data

Hi,

As the title says, I tried running humann3 on the demo data but found 100% unaligned reads. I’m guessing that this shouldn’t be the case?

My command is:
humann --input demo.fastq.gz --output demo_fastq

The output is:
Running bowtie2 …

Total bugs from nucleotide alignment: 0
Total gene families from nucleotide alignment: 0
Unaligned reads after nucleotide alignment: 100.0000000000 %

Running diamond …

Aligning to reference database: uniref90_201901b_full.dmnd

CRITICAL ERROR: Error executing: /home/user/miniconda3/envs/humann3/bin/diamond blastx --query /home/user/metagenomics/results/humann_demo/demo_humann_temp/demo_bowtie2_unaligned.fa --evalue 1.0 --threads 1 --top 1 --outfmt 6 --db /home/user/metagenomics/databases/humann/uniref/uniref90_201901b_full --out /home/user/metagenomics/results/humann_demo/demo_humann_temp/tmpja7rf3jq/diamond_m8_rm_2z37c --tmpdir /home/user/metagenomics/results/humann_demo/demo_humann_temp/tmpja7rf3jq

Would greatly appreciate any help or advice. Thanks!

Make sure you are running the version of the demo specific for your HUMAnN version. They are highly specialized for efficiency, so (for example) the v3 demo input probably won’t produce any output on the v4 demo databases.