Group Chats "Cannot read property 'find' of undefined"

[Jakapoa]

Restarted Steam, and upon opening a group chat these errors were generated. The member panel is now empty. I am not using a custom skin.

Error: "Cannot read property 'find' of undefined"   (x) Dismiss
TypeError: Cannot read property 'find' of undefined
    at e.GetBucketIdForPlayer (https://steamcommunity-a.akamaihd.net/public/javascript/webui/friends.js?v=d5uPajrL2Mk0&l=english:14:646163)
    at e.PerformInitialPopulate (https://steamcommunity-a.akamaihd.net/public/javascript/webui/friends.js?v=d5uPajrL2Mk0&l=english:14:644348)
    at e.RegisterForGroupMemberList (https://steamcommunity-a.akamaihd.net/public/javascript/webui/friends.js?v=d5uPajrL2Mk0&l=english:14:638430)
    at new e (https://steamcommunity-a.akamaihd.net/public/javascript/webui/friends.js?v=d5uPajrL2Mk0&l=english:14:784985)
    at jo (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:47929)
    at si (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:56743)
    at hi (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:63203)
    at Vi (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:77557)
    at qi (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:77932)
    at Ra (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:84001)
The error occurred while rendering:
    in e
    in div
    in e
    in div
    in div
    in div
    in e
    in div
    in div
    in div
    in div
    in div
    in div
    in div
    in e
    in e
    in e
    in div
    in div
    in e
    in e
    in div
    in t

Error: "Cannot read property 'find' of undefined"   (x) Dismiss
TypeError: Cannot read property 'find' of undefined
    at e.GetMemberPartyBeacon (https://steamcommunity-a.akamaihd.net/public/javascript/webui/friends.js?v=d5uPajrL2Mk0&l=english:14:332635)
    at e.render (https://steamcommunity-a.akamaihd.net/public/javascript/webui/friends.js?v=d5uPajrL2Mk0&l=english:14:803934)
    at X (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:37:6371)
    at https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:92:15384
    at pe (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:37:12332)
    at e.track (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:37:16751)
    at e.r [as render] (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:92:15297)
    at e.<anonymous> (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:92:16107)
    at e.F.l.render (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:92:16119)
    at ui (https://steamcommunity-a.akamaihd.net/public/javascript/webui/libraries.js?v=TYROzI9DRz0y&l=english:108:59597)
The error occurred while rendering:
    in e
    in div
    in div
    in div
    in f
    in a
    in div
    in e
    in div
    in e
    in div
    in e
    in div
    in div
    in div
    in e
    in div
    in div
    in div
    in div
    in div
    in div
    in div
    in e
    in e
    in e
    in div
    in div
    in e
    in e
    in div
    in t

[DarkCrystalMethod]

https://steamcommunity.com/discussions/forum/10/1736595227837508752
This was only solved by forcing steam to check for updates
Steam->Check for Steam Client Updates
And then it worked.