If current server doesn't work please try other servers below.
Season 1 - Jan. 18, 2015
Season 2 - Jul. 11, 2016
Season 3 - Jul. 15, 2017
Season 4 - Mar. 10, 2019

Star vs. the Forces of Evil Season 4 Episode 15
HD
Overview:
Moon revisits the Butterfly Castle ruins to discover an item she left behind, but she is soon surprised.