I don't know for sure if it actually IS CensusPlus that does this or something else (other addons are also reporting the same error, so it might me something completely different)..
3x [ADDON_ACTION_FORBIDDEN] AddOn "CensusPlus" tried to call the protected function "IsDisabledByParentalControls()".
!BugGrabber-r198-release\BugGrabber.lua:552: in function <BugGrabber>
<in>
FrameXML\MainMenuBarMicroButtons.lua:229: in function "UpdateMicroButtons"
FrameXML\FriendsFrame.lua:258: in function <FrameXML>
<in>
FrameXML\UIParent.lua:1819: in function "SetUIPanel"
FrameXML\UIParent.lua:1663: in function "ShowUIPanel"
FrameXML\UIParent.lua:1545: in function <FrameXML>
<in>
FrameXML\UIParent.lua:2262: in function "ShowUIPanel"
FrameXML\FriendsFrame.lua:906: in function "WhoList_Update"
CensusPlus-6.1.0\libs\LibWho-2.0\LibWho-2.0-125.lua:891: in function "?"
CensusPlus-6.1.0\libs\LibWho-2.0\LibWho-2.0-125.lua:916: in function <CensusPlus>
Locals:
nil
Doing census mainly on Draenor; Raluf - Nimsay - Lusmo - Quixx - Sosyan - Garthog - Trubin - Zalistra - Zesmi and Djaang
Apparently, this bug is fixed on the PTR running 5.4.2 (haven't tried myself but a number of people are reporting it), which goes live this week. So you may be able to remove that temporary fix soon, will update when the patch goes live over here
(Was about to post it on the main thread on the subject but figured bumping an old announcement will just confuse everyone, so posted here instead )