Unable to activate plugins

Within the past couple days one the plugins on one of our clients sites (awareak.org) deactivated for an unknown reason. When I was in the dashboard today to reactivate it, the other active plugins deactivated (when I clicked “activate” on plugin A, plugin B and C deactivated).

Now none of the plugins will activate. When I click “activate” on one, I receive the “plugin activated” success message, though nothing actually activates: http://note.io/1HdnNo1

Please advise, this is effecting important features of their site.

Thank you,
-Michaela