New Plugin menu never opened

I followed the instructions sent out and installed the new Event Calendar plugin. I expected the original plugin to be replaced by it, but it wasn’t. Not a big deal, though. I activated it on my multisite network and went to the one site where it’s currently in use.

However, when I tried to open the new Timely menu, it never opened. I got a spinning wheel, but never anything else.

I have deactivated this plugin for now. Another odd issue appeared at the same time and may or may not be related. I’m getting the annoying “Cookies are blocked are not supported by your browser” message whenever I try to View Details for any of the plugins I use on that particular site. I do not get this issue when I view plugin details for any of my other sites. Only on the one using Time.ly. That is the only difference between it and the other sites on my network.

I suppose that could be a separate issue, but it’s an odd coincidence that it only happens on this site.