I had this issue – weirdly, the AdBlock Chrome extension hides this plugin from the list of installed plugins !
(Click the AdBlock icon and select ‘don’t run on this page’ – the page will auto-refresh and this plugin will appear on the list !)
So, what if you don’t have AdBlock? I’m having this problem too, and I need to deactivate and reactivate it but I can’t.
Despite the fact that AdBlock should NOT hide this on the plugins list, why would someone that earns money with AdSense have AdBlock installed at all?
There appears to be 2 different issues here, one of them caused by AdBlock, and a second one with an as yet unidentified cause.
