[gess99]

After the publication of the notice in the forum, open the page on which is written (on this page is detected cyclic redirect)

[Robin W]

With so little information it is hard to help !

It could be a theme or plugin issue

Plugins

Deactivate all but bbpress and see if this fixes. if it does, re-enable one at a time to see which is causing the error.

Themes

If plugins don’t pinpoint the problem, as a test switch to a default theme such as twentytwelve, and see if this fixes.