JError:1 on Logout

The logout process uses the standard Joomla logout process. My guess is that either a) you've set the Logout Redirection to a page that isn't working or b) there is some user or system plugin that's detecting the logout and then doing something it shouldn't.

I'd recommend trying with the standard mod_login module to see if you have the same issues. If so, that narrows it down to not just being an SCLogin issue but something underlying within Joomla.

I hope that helps get you started, but if you continue to have issues, just let us know.

Thanks,
Alex