WowAce

Both WeakAura and Bartender are mentioned, so not sure which addon is at fault so I'll report to both of you.

304x ...tender4\libs\LibButtonGlow-1.0\LibButtonGlow-1.0-6.lua:234: attempt to index local 'frame' (a nil value)
...tender4\libs\LibButtonGlow-1.0\LibButtonGlow-1.0-6.lua:234: in function `HideOverlayGlow'
WeakAuras\WeakAuras-2.5.7.lua:334: in function `ActionButton_HideOverlayGlow'
[string "--[[ Error in ' Explosive Orbs ' ]]return f..."]:13: in function `glow'
[string "--[[ Error in ' Explosive Orbs ' ]]return f..."]:21: in function `triggerFunc'
WeakAuras\GenericTrigger.lua:542: in function <WeakAuras\GenericTrigger.lua:510>
WeakAuras\GenericTrigger.lua:600: in function `ScanEvents'
WeakAuras\GenericTrigger.lua:979: in function <WeakAuras\GenericTrigger.lua:977>

Locals:
frame = nil
(*temporary) = nil
(*temporary) = nil
(*temporary) = "attempt to index local 'frame' (a nil value)"
OverlayGlowAnimOutFinished = <function> defined @Bartender4\libs\LibButtonGlow-1.0\LibButtonGlow-1.0.lua:44

This is a WA problem, it tries to hide the glow on a frame which doesn't exist.