Joe Spraga 
put a space after your name in edit profile, then : bc : BUT NO SPACES IN COLONS, OR COPY/PASTE WITH A SPACE AFTER YOUR NAME
MikeVV 
@mikevv ok go to your about section of your instance, then see who the admin is, then message them to update the code on the server so it will work🙂
@joespraga found the root cause. My instance just does not have this emoji in the list https://emojos.in/mastodon.social will ask if it possible to add that 🙂