After all needed patches have been applied, selecting Continue will set everything up to update the system module. This is a very important step and is required to complete the upgrade properly.
Select Update to perform the update of System module.
XOOPS ships with three optional modules - pm (Private Messaging,) profile (User Profile) and protector (Protector) You should do an update on any of these modules that are installed.
It is likely that there are updates to other modules that might enable the modules to work better under your now updated XOOPS. You should investigate and apply any appropriate module updates.
If you followed the advice to Turn your site off, you should turn it back on once you have determined it is working correctly.