https://britastro.org/observations/observation.php?id=20181111_015500_44cd9ab1092010e3 contains a reference to https://britastro.org/node/19348 (this is just a specific example of no importance otherwise), which link is now broken. I can easily fix isolated examples in my own pages but perhaps they may be corrected globally with a script? AFAICT, and assuming the old pages are still available in an archive somewhere, a relatively straightforward pattern matching exercise should match old with new URLs.
We already have a script which does this, but apparently it’s not working properly. I shall flag this up with the relevant individual.