6x alaTradeSkill/ui.lua:2796: bad argument #1 to 'SetText' (Usage: self:SetText([text]))
[string "=[C]"]: in function `SetText'
[string "@alaTradeSkill/ui.lua"]:2796: in function <alaTradeSkill/ui.lua:2795>

Locals:
(*temporary) = FontString {
 0 = <userdata>
}
(*temporary) = TipText {
 0 = <userdata>
}

Happens when you mouse-over the filter checkboxes, Known , Unknown etc

I'm going to guess you meant the OnEnter to be something like this instead

	function LT_WidgetMethod.SetFrameCheckButton_OnEnter(self)
		local TipText = l10n[self.key.."Tip"]
		self.TipInfo:SetText(TipText);
	end

All of the :SetText(nil) will also similarly error and should probably be replaced with :SetText("")

Fixed in latest

yep. Updated
It is strange that I didnot produce this error. Probably there is an addon fix it.