Just discovered this today while tooling around, I've tried all the new 4k skins as well as the old skins and it seems "loved" has taken over the place of "starred" items. I can get to the starred page by manually typing it in, but the icon is gone from the side navigation bar.
~Upon further investigation, logging in with a non-admin account shows the icon. I guess it's just an admin issue.
Version MADSONIC 6.2.9040.9b189e7.20161208.0411 - IP address [192.168.1.100]
REST MADSONIC REST API v2.5.0, SUBSONIC REST API v1.14.0
Server jetty/8.y.z-SNAPSHOT, java 1.8.0_101, Windows 10 10.0 (amd64) (139.4 MB / 481.0 MB)
Size: Database: 667MB, Thumbs-Cache: 70MB, LastFM-Cache: 48MB, Lucene-Cache: 10MB
Spring.Framework v3.2.17, Spring.Security v3.2.9, HyperSQL DataBase v2.3.4