Hello,
Pardon our bumps as we are transitioning. You can see the announcement here:
The master branch has updated links to the new doxygen location:
https://simpleitk.readthedocs.io/en/master/filters.html
I have put a request into Kitware to forward the old SimpleITK doxygen URLs to the new location. Hopefully the errors you can encountering is an indication that the fix is on the way.
It some ways it’s good to know our hiccups were noticed. 