The JPO has issued a warning that the ST.26 format sequence table created using WIPO Sequence 2.1.0 may be missing the required field "Feature Table".
The JPO recommends the use of the latest version of WIPO Sequence 2.1.2, as this issue is resolved in the latest version.

According to WIPO, when you create a sequence table using WIPO Sequence, use the validation function on the tool to check if there are any problems with the created sequence table, and if the result shows a message that the "Feature Table" is missing, you need to create the sequence table again following the procedure announced on the WIPO website.
Details can be found at the URL below.

Japan Patent Office
https://www.jpo.go.jp/system/patent/shutugan/bio/gene/enki_amino_wipo.html#about_wipo_sequence