I know this is not going to help you but,,
The proper procedure requires that you keep everything current. That means "latest ISO and a full update" following the instal, then regular updates to keep the OS current and in working order.
If you are doing something with an old version that was not kept up to date, I would recommend you backup all of your personal data to an external disk, install the latest ISO of your choosing, do a complete update and then restore your data.
Then, do regular updates and enjoy.