In 10.1 when enabling "fade" and "button hide", the scroll bars and arrows persist when logging in for the first time or doing a /reload, until you mouse over the chat window:

Yeah i would love to hide that scrollbar. Its showing every time when something pop in the chat.

Cannot reproduce the scrollbar showing up every time something new is added to chat.

I can reproduce it showing when you log in, however, that happens even with BCM turned off.

I can reproduce it showing when you log in, however, that happens even with BCM turned off.

OK, so that must be a Blizzard bug then.

Its a known blizzard bug. To reproduce - mouseover chat to fade it IN. Instantly /reload before it fades out. When UI appears again, chat will be hidden, but scroll wheel appears.

Can also easily reproduce by hiding the UI keybind. Make chat fade in, hide UI, give it some time for fade out to happen, then re-enable UI. Scroll is there.

Oh, awesome! Will just wait it out then :) not a big deal

Any update on a fix for this?
Prat has already found a way to resolve this - maybe use their code as a guide?
Please and thank you..

I reported it to Blizz and they have already implemented a fix in 10.1.5 PTR which you can test if you wish on the PTR realm.

Closing, should be resolved in today's WoW patch.