Found this question: Wordpress: http://stackoverflow.com/questions/29570326/wordpress-media-library-grid-mode-infinite-loading
And, more recently: "Currently I am using Enfold child theme but media grid view is not working. Even if I try to get to the grid from any of other places like selecting the featured image its not working." From: http://stackoverflow.com/questions/37666217/wordpress-grid-media-is-not-working/37788781#37788781
I am having the exact same problem in WordPress (and also using Enfold). I have renamed my plugins folder to plugins.hold, disabling all plugins. I also set the theme to TwentySixteen. Neither of those things worked. The media library list view works -- only the grid view does not. (But, this is vital, since several elements in this theme pull from the grid view by default with no chance to switch to the list view. This essentially renders those elements useless, as it is impossible to add an image.)
I tagged this as multisite because this site is part of a multisite. Not sure that has anything at all to do with the problem, but not sure it doesn't, either. It is currently the only site on the multisite.