There are many pages in the documentation that point to https://github.com/duplicati/documentation/tree/main/detailed-descriptions/duplicati-programs which doesn’t seem to exist anymore.
For instance: The local database | Duplicati :
Duplicati uses two databases, …
Thanks for reporting!
I did a re-organization of some of the articles to make it easier to navigate, and it looks like some relative links were not correctly updated.
I have gone through it again, and the links should work correctly again.
Let me know if you find a link that is not working.