I have needed to remove the WPMU Dash from my plugins since it has been causing my admin panel dash to disappear when active. I removed the folder completely. When I removed it, my wp admin dash is visible again. I went ahead and downloaded the "add new users" plugin from WPMU as a standalone file and activated it. It also caused my admin panel to disappear, but it appeared again once I deactivated the plugin. My site seems to not like any of the WPMU plugins. Can we verify the issue? Perhaps this is due to the removal of the dash?