WowAce

Video showing how the error happens. https://www.youtube.com/watch?v=O7sU9u0xBbI&feature=youtu.be

4x GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0-36.lua:697: Action[SetPoint] failed because[SetPoint would result in anchor family connection]: attempted from: <unnamed>:SetPoint.
[C]: in function `SetPoint'
GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0-36.lua:697: in function <GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0.lua:655>
[C]: ?
GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0-36.lua:71: in function <GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0.lua:69>
GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0-36.lua:407: in function `PerformLayout'
GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0-36.lua:412: in function `DoLayout'
GalvinUnitBars\Libs\AceGUI-3.0\AceGUI-3.0-36.lua:433: in function `AddChild'
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0-73.lua:1634: in function `FeedGroup'
...nfig-3.0\AceConfigDialog-3.0\AceConfigDialog-3.0-73.lua:1873: in function `Open'
GalvinUnitBars\Options-Options.lua:866: in function <GalvinUnitBars\Options.lua:854>
GalvinUnitBars\Options-Options.lua:875: in function <GalvinUnitBars\Options.lua:873>
GalvinUnitBars\Options-Options.lua:890: in function <GalvinUnitBars\Options.lua:889>
...
(tail call): ?
...\AceConfig-3.0-3\AceConfigCmd-3.0\AceConfigCmd-3.0-14.lua:769: in function `HandleCommand'
...\AceConfig-3.0-3\AceConfigCmd-3.0\AceConfigCmd-3.0-14.lua:781: in function `?'
FrameXML\ChatFrame.lua:4836: in function <FrameXML\ChatFrame.lua:4783>
[C]: ?
[C]: in function `ChatEdit_ParseText'
FrameXML\ChatFrame.lua:4497: in function <FrameXML\ChatFrame.lua:4496>
[C]: in function `ChatEdit_SendText'
FrameXML\ChatFrame.lua:4533: in function `ChatEdit_OnEnterPressed'
[string "*:OnEnterPressed"]:1: in function <[string "*:OnEnterPressed"]:1>

Locals:
nil

Ok did a second test.  Just like in the video.  The difference is I don't try to move the separator bar thingy.  I just make the window wider, then close and reopen.

So my thinking is the error is related the the bar you can drag left and right to make the treeview wider or narrower

Try with the latest alpha version, it may fix it.