Param contact_email must be a valid email address

That's an issue with Facebook itself rejecting that email address. We don't have any control over that, unfortunately.

I'd recommend either:
1) Trying to set the Contact Email directly in the Facebook Developer Area . That may work as it doesn't have to go through the same API that we have to go through with Autotune. If this works, simply hit the "Refresh" button in the Autotune area to reload the new settings and (hopefully) be able to save them back again with any changes.
2) Use a more standard email address that Facebook won't have issues with.

Sorry I don't have a magic bullet fix.

Alex