Error #1
I'm assuming you're getting this on Login? I've never seen that issue before, but here are my suggestions:
1) Make sure you've run Autotune and had it setup your Facebook Application properly. In particular:
a) the "FB App" section should have no "red" recommendations.. or, if they are red, you understand why.
b) The "Error Check" tool reports no errors.
Error #2
The redirect_uri_mismatch error means you haven't properly setup your Google Application. Please make sure you've setup the app according to our
Google Application setup guide
. Specifically, check step 7-4 for your callback URLs.
I hope that helps, but if not, let us know, and we can help investigate further.
Thanks,
Alex