I've suddenly started having an issue with the "One or more plugins have been activated or deactivated, please empty the page cache" message not going away. I empty the page cache and it disappears, but the next time I reload a screen it's there again. "Hide this message" doesn't work either.
I'm running 3.6.1 multisite - weird thing is this is only happening for one of my sites (the main site). No issues in network admin or the any of the other sites.
Any ideas? Thanks!