Can't playback my score on Musescore.com

I just finished a new piece and saved it online on Musescore.com But it doesn't seem to be playing back my music. The playback button is there but when I hover over it, it doesn't show that I can play it, and it won't play when I click on it. Is it because it's too huge of a file or is there something more? Btw, I still use Musescore 2.3 or whatever version is before Musescore 3.