Well, that is very interesting. I guess it is a theme thing.
Changed settings under Interface from Horizon to Endeavour theme and now the scrollbar is visible when clicking to choose an emoji.
Personally, I would prefer a smaller set but I will go with whatever the community decides.
This might be something to file as a bug over at Meta?
Thanks
Edit: I checked over at Meta, where they also use Horizon. No issues…but then again they are only using 14 emojis for post likes.
I went and done some research and this looks like an issue related to max-height CSS rule being interpreted by the browser or a bug in the forum’s CSS or HTML structure. It can also be some extension (Ad-blocker or other privacy oriented extension) that breaks CSS rules.
Balls are hard to come by in this time and age 
Yeah, it is theme related. i changed to endeavour dark and now i have the scrolling back.
Welcome to the club! 
Thank you all for investigating! Since I didn’t change the Horizon theme. Codewise, I’m afraid I cannot do anything to solve the issue.
And put the pitchforks and torches back in your sheds and attics, I reinstalled the sports balls again… 
@rubi1200 As for the Discourse forum, don’t call them Meta, that’s another tech company. Meta means discussion. 
Their menu doesn’t scroll either, they just have those two rows of emojis.
As you can read, the community over here is very protective of their emoji choices…
