GetRuneCooldown will crash your client

[galvin]

Posted this on the official forums a while back.

If you're not a death knight and you call this function it'll crash the client.

Work around I use in my mod

local GetRuneCooldown1 = GetRuneCooldown

local function GetRuneCooldown(RuneIndex)
  if Main.PlayerClass ~= 'DEATHKNIGHT' then
    return 0, 0, true
  else
    return GetRuneCooldown1(RuneIndex)
  end
end

[galvin]

Fixed in last beta update

Returns nil if you're not a deathknight.

[p3lim]

I wonder if they fixed this issue as well:
https://github.com/haste/oUF/pull/251/files