Database DB_merge_clu_rep needs header information

[qkqk-hub]

No error occurs when I run with the following command:

mmseqs createdb ./*.faa .. /mmseqs_DB/DB_1
mmseqs linclust DB_1 linclu_1 ../all_reference_protein_faa --min-seq-id 1 --cov-mode 1 -c 0.8 --kmer-per-seq 80 --remove-tmp-files --threads 25
mmseqs createsubdb linclu_1 DB_1 DB_1_clu_rep
mmseqs convert2fasta DB_1_clu_rep DB_1_clu_rep.fasta

However, when I generate multiple databases and merge them, an error occurs:

mmseqs createdb ../DB1/*.faa .. /mmseqs_DB/DB_1
mmseqs createdb ../DB2/*.faa .. /mmseqs_DB/DB_2
mmseqs mergedbs DB_1 ../mmseqs_DB_merge/DB_merge DB_2
mmseqs linclust DB_merge linclu_merge ../all_reference_protein_faa --min-seq-id 1 --cov-mode 1 -c 0.8 --kmer-per-seq 80 --remove-tmp-files --threads 25
mmseqs createsubdb linclu_merge DB_merge DB_merge_clu_rep

No errors have been generated so far.
An error occurs when I run the following code:

mmseqs convert2fasta DB_merge_clu_rep DB_merge_clu_rep.fasta

The error message is as follows:
Database DB_merge_clu_rep needs header information

Is it mmseqs mergedbs DB_1... /mmseqs_DB_merge/DB_merge DB_2 Is there an error in this step?

Thank you for your reply!

With best wishes!