I almost always have to run “/reloadui” daily in my game client, I always have since vanilla days. I realize “/reload” is there but for some reason last night, “/reloadui” no longer works. When I run the command I now get “Type ‘/help’ for a listing of a few commands.”.
NOTE: “/console reloadui” does work.
I tried disabling all addons, removing Interface/WTF/Cache folders, reinstalling virgin client, and attempted the command on another machine altogether and the command still has the same behavior. I am thinking maybe this isn’t a command but an alias provided by some mod?
I will also note, that I asked several players in-game and they all said “/reloadui” worked for them…
Hey there, Woake!
Thank you for taking the time to report this. I do recall that the native “/reloadui” command used to work and function the same as “/reload”, but after testing this on my game client, I can confirm that the former (“/reloadui”) no longer works. I was not able to find official communication as to when this change was made, but rest assured that this is not isolated to your game client.
With that in mind, you should be able to continue using the “/reload” command as normal. 
Thank you for your reply. I did some more testing, it appears that if you have a lua error then “/reloadui” does work. That was my problem, I had always had a lua error and dismissed it, and recently fixed the offending module. I didn’t put 2 and 2 together until further testing.
If you enter “/luaerror on” then “/reloadui” works… It must be a debug only thing now?