WowAce

Message: ...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:234: script ran too long
Time: 07/04/17 19:26:37
Count: 1
Stack: ...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:234: script ran too longInterface\SharedXML\SharedBasicControls.lua:204: in function <Interface\SharedXML\SharedBasicControls.lua:203>
[C]: in function `CreateFontString'
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:234: in function <...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:216>
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:537: in function <...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:522>
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:599: in function <...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:587>
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:654: in function `?'
...nterface\AddOns\ShadowedUnitFrames\modules\units.lua:36: in function `FullUpdate'
...nterface\AddOns\ShadowedUnitFrames\modules\units.lua:370: in function `?'
...nterface\AddOns\ShadowedUnitFrames\modules\units.lua:209: in function <...nterface\AddOns\ShadowedUnitFrames\modules\units.lua:206>

Locals: errorMessage = "...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:234: script ran too long"
DisplayMessageInternal = <function> defined @Interface\SharedXML\SharedBasicControls.lua:187
MESSAGE_TYPE_ERROR = 0

Sometimes under heavy load updateButton fails in the middle with messages like above ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^.

Since updateButton itself and all other functions assume that if button is created, everything else is created too, it causes tons of errors like those below (notice the COUNT!).
vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

Message: ...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:546: attempt to index field 'border' (a nil value)
Time: 07/04/17 19:41:19
Count: 3506
Stack: ...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:546: attempt to index field 'border' (a nil value)Interface\SharedXML\SharedBasicControls.lua:204: in function <Interface\SharedXML\SharedBasicControls.lua:203>
[C]: ?
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:546: in function <...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:522>
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:599: in function <...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:587>
...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:654: in function `?'
...nterface\AddOns\ShadowedUnitFrames\modules\units.lua:209: in function <...nterface\AddOns\ShadowedUnitFrames\modules\units.lua:206>

Locals: errorMessage = "...nterface\AddOns\ShadowedUnitFrames\modules\auras.lua:546: attempt to index field 'border' (a nil value)"
DisplayMessageInternal = <function> defined @Interface\SharedXML\SharedBasicControls.lua:187
MESSAGE_TYPE_ERROR = 0

----------------------------------

Message: ...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:12: attempt to index field 'cooldown' (a nil value)
Time: 07/04/17 19:54:20
Count: 49579
Stack: ...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:12: attempt to index field 'cooldown' (a nil value)Interface\SharedXML\SharedBasicControls.lua:204: in function <Interface\SharedXML\SharedBasicControls.lua:203>
[C]: ?
...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:12: in function <...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:6>
...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:26: in function <...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:23>

Locals: errorMessage = "...nterface\AddOns\ShadowedUnitFrames\modules\fader.lua:12: attempt to index field 'cooldown' (a nil value)"
DisplayMessageInternal = <function> defined @Interface\SharedXML\SharedBasicControls.lua:187
MESSAGE_TYPE_ERROR = 0

You should check not only that button exists, but that its last possible child (.icon) is created too. Also you need to save UI objects to your data structures only after you've completed the entire one time set-up.

I've attached a patch that does just that.