Infinite error loop on multilanguage sites
From Joomla! Documentation
In some multilingual sites that were created before Joomla 2.5.4 when upgrading to 3.4 you can have a redirect loop created.
Infinite redirect in browser when attempting to visit multilingual site.
What is the cause
In Joomla 2.5.4 and earlier the access level was not correctly stored in the database and as a result a value of 0 was obtained. This therefore then fails against the access check in the language filter plugin creating a redirect loop.
How to fix
Edit each content language in Language Manager and ensure a access level (generally public) is set for each installed language.