Hi
The credentials to view multiple languages are not correct (Username and password do not match or you do not have an account yet.), but I was able to login to the frontend with the admin access provided.
I have reviewed all settings and couldn't find anything. It's only this page that causes an issue, I couldn't see any other so far. Did you?
First thing first, as the error is a Gantry one (and yes, I know it happens only when sh404SEF is enabled, but that absolutely don't mean it's caused by sh404SEF), what do they say about the error?
"/home/silver/public_html/plugins/system/gantry5/gantry5.php158 -> Call to a member function setLayout() on a non-object
?
Rgds