Hi Junying,
Please look at your ‘Overview’ tab if a reference to define.xml file is included.
In P21 Community you need to run 2 separate validations for define.xml file.
First, validate define.xml using Define-XML standard. The tool will check you define.xml file for compliance with CDISC Define-XML standard and some additional things like FDA/PMDA requirements, correct representation of CDISC CT, etc.
Then, when validating study datasets you need to add define.xml file to check consistency of your specified metadata vs. datasets.
I assume that you 1. skipped the first step and 2. do not have any define.xml/datasets issues.
Kind Regards,
Sergiy