If you delete the files via ftp and add via the plugin panel, you can activate it, but it does not show up in the plugin list NOR does it work. I am just looking at this myself – the widget is in the sidebar, but no ads appear. Just upgraded WP today to the most recent version.
I can not add plugins via the plugin panel, because I use plugin askapache-password-protect.4.6.6, which is a great plugin for all security and for me has priority over all other plugins.
For some reason it blocks the panel for upload, probably one of the security features
I do not know why that is, so I must use FTP for installing new plugins.
But also in my book plugins, that do not comfore to standarisation are not worth using anyway. For every plugin there are always other substitutes that do function correctly