Step one, of course, is to read the release notes:
https://jefftucker.net/mercury/man/MEreleasenotes.html
The latest
Mercury release includes one new option (regarding favicons), and changes the internal help links in the UI (the "question mark in a little circle" icon at the top right of each panel). But the old help links will work just as well, so this is non-critical (the manual is actually present on both my jalbum.net account and on my own webhost - all identical).
If your album does everything you want it to do, and you don't want to use whatever new feature was introduced in the update, then there's no real reason to make the album again.
But if the update includes any bug fixes, you should jump on it. Open each saved project, immediately save it again (CTRL-S), so that the saved "what version was used to make this album" variable gets updated and saved, then make the album and upload it again.
If you do make the album again, of course, make sure you're
not telling jAlbum to process only updated subdirectories. That can make a mess of things.
