Every TW version has a library-config tiddler. They are tagged: $:/tags/PluginLibrary and point to the TW library URLs.
See: https://tiddlywiki.com/#%24%3A%2Fconfig%2FOfficialPluginLibrary for v5.3.2
For archived versions this config tiddler will point to the respective library.
So if you need to downgrade a wiki, IMO the best way is to
- Backup first!
- Open empy.html from the archive
- Import your existing wiki
- Import everything
- Open $:/ControlPanel → Plugins tab
- Click the Get more plugins button
- Since the library config file points to the archived version you should see
- a red “downgrade” button for existing core plugins
Important
Downgrading over TW major versions like v5.3.x → v5.2.x should be avoided if you did modify core UI templates. Newer UI templates may use features, that are not present in older versions.
Downgrading is possible since v5.1.22. So versions below this version do not show that button
Hope that helps
-mario