Meteor Slides not working on multisite

I can’t get Meteor Slides to display in a widget on a multisite subsite. If you look at the bottom right-hand column of litcrawl.org/sf, you *should* see a series of rotating ads–I only see a white space. I do have Meteor Slides network activated.

The same Meteor Slides widget is working on a single-site installation (litquake.org) which uses the same theme, child theme, plugins, etc. as the multisite installation.

Any ideas?

(I saw a previous post reporting this problem, but it was marked resolved once the plugin was Network Activated. My plugin is Network Activated but still not working.)