Hi @XiongGZ
Could you show me the commands you use when adding the --index or the --bowtie2db ? can you also show me the content of the /opt/service/miniconda3/envs/vep_env/lib/python3.7/site-packages/metaphlan/metaphlan_databases folder?
Thanks for your help!
(I have solved this problem by using the custom database folder, and I found the default folder does not contain the *.bt2l files.)