I just downloaded and installed the Instagram Feed Widget and am missing the user and thumbnail options from the options box. The lightbox settings do work, but the widget is pretty un-usable if I can't change what user's feed I'm displaying. I'm missing the options in the Legacy version of the plugin as well, and have tried closing and restarting Muse, and creating a new site to test the plugin on. Muse 2015.1 Instagram Feed 1.2 and L.11.3 OSX 10.10.5
Amy, the widget has two fly out panels, the one you are showing and the one that is from the display area (little blue arrow when you click on the camera icon area. Dj