When I input: qiime metadata tabulate --m-input-file taxonomy.qza --m-input-file rep-seqs.qza --o-visualization taxo-table.qzv, it worked fine. However, when I input: qiime metadata tabulate --m-input-file taxonomy.qza --m-input-file table.qza --o-visualization taxo-table.qzv, it did not work, with error message: cannot merge because there are no IDs shared across metadata objects. I am wondering why the ids in table.qza and repseqs.qza are not shared and how to solve this problem. Thanks in advance for your help.