Mattermost 5.12.4 Emoji Picker freezes desktop client

Summary

Upgraded to 5.12.4 and Emoji Picker screen freezes Mac desktop client running Mojave

Steps to reproduce

5.12.4 on RHEL7 vm. Users are using 4.2.1 Desktop Mac client on Mojave.

Expected behavior

User clicks on Emoji picker screen. Mouse should move freely between emojis and then you can click on an emoji and it shows up in your chat bar.

Observed behavior

User clicks on Emoji picker screen. Move mouse over emoji’s and it is very slow with lag. Will then randomly freeze desktop client. Have to go to toolbar and Clear Cache & Reload to get it to come back.

Sounds like that: https://mattermost.atlassian.net/plugins/servlet/mobile?originPath=%2Fbrowse%2FMM-17272#issue/MM-17272