Since we updated the domain mapping plugin on this site, we're having major issues with being redirected to https when trying to access wp-admin.
The problem is that this server is not configured for SSL, so when we try and carry out an action that redirects us to SSL (post, trash post, activate/deactivate plugins, etc) then we're sent to a 404 page.
It's made the entire network unusable.
I have provided it's domain mapping by disabling it, although this has the undesired effect of taking all the sites that run off it down at the same time.
What do you propose as a solution?