We have upgrade word press from 3.8.3 to 4.1.40 on 17th, Jan,2025.

Just stop web server, and rename the old site directory name, and rename the 4.1.40 to original directory name, chmod the right of directories. Copy the upload content if it exists.

Execute the wp-admin/upgrade to alter the database structure.

Excute the Permalinks to re-generate the pages link.

Stay for a while, and remove snapshot on vps and backup.

Finally, we could use WordPress app on ipad of  ios 17.