What do you mean no apparent upgrade script?
This is right from the upgrade instructions
3) Depending on which upgrades you need, you should upload all these files to the MAIN PHOTOPOST DIRECTORY (or, for advanced user, |
upload only those scripts you need to execute).
4) Run upgrade.php and depending on your version, run any necessary upgrades.
Plus this is right from the announcement thread to all users here PhotoPost 4.8.5 Released! Upgrade Instructions
There is an upgrade482.php file you need to run which is meantioned. You will recieve an sql error until you run that as your the scripts are looking for an uplimit field in your usergroups table which of course does not exist yet.