When starting a new repository the index page (Admin -> Configuration) shows /home initially this redirects to /index. If you change this string to something else and then back to '/home' browsers report a redirect loop.

What happens: Fossil stores the index page in table 'config' with key 'index-page'. Initially this record does not exist, and you get redirected to /index. Modifying the configuration overrides the default behavior. It is impossible however to get the original behavior back.
 
The problem is that setting the string back to '/home' keeps the record in 'config', which causes the problem. Running "delete from config where name = 'index-page';" restores the original behavior and gets rid of the redirect loop.

Suggestion: remove the record when the admin sets the index page to '/home'.