Sitecore 8 - 404 error when changing language in experience editor

Question

I have set up a new role in my Sitecore 8 (update 3) instance and have assigned the following roles to it (as well as giving read/write access to my content tree):

sitecore\Sitecore Client Translating
sitecore\Sitecore Client Users
sitecore\Sitecore Client Authoring
sitecore\Sitecore Client Designing

When logged in and using the Content Editor, I can change language ok. When I change language in the Page Editor Experience Editor however, (using Experience > Language menu item) I get a 404 error. If I clear the URL in the browser to the root (hostname) the language appears to have been changed.

Edit: Additional Information

It's worth noting that:

1. The solution does not use translated items. We have a separate content tree (within a single instance) for each site/language.
2. The linkManager is configured to use DisplayName for the URL.

Answer 1

Please share the snapshot of your new content tree structure and link manager config settings if possible. Meanwhile, can you please revert link manager settings and check if it works fine? Also use firebug net tab with persist to see the URLs requested while click on second language.

Also, please check following cookies values if updated your-site-name#lang:- website#lang

here webiste is name of default sitecore site

Moreover, when your Experience Editor is loaded, just to make sure, click on default language from language menu to see if it works even for default language.

As said keep your firebug open with persist and keep eye on net tab with all to see if any resource request having 404.